How to Track Ovulation With PMOS (PCOS)

If you have PMOS (polyendocrine metabolic ovarian syndrome, formerly PCOS), figuring out when or whether you’re ovulating can feel a little like trying to hit a moving target. While you can track ovulation with PMOS, the usual methods can be less reliable. The good news is that with the right combination of methods, and the right timing, you can build a clear picture of whether and when you’re ovulating.

Quick facts

• PMOS often causes irregular, long or unpredictable cycles, which makes ovulation harder to pin down, and sometimes it doesn’t happen at all (an anovulatory cycle).
• Standard ovulation predictor kits (OPKs) are less reliable with PMOS, because chronically high LH can trigger repeated false positives or mask the true surge.
• OPKs only predict ovulation, they can’t confirm an egg was actually released.
• A progesterone blood test is the most reliable way to confirm ovulation happened, but the timing has to be adjusted if your cycle is long or irregular.
• If you’re not ovulating regularly, that’s common with PMOS and often very treatable, many people conceive naturally or with ovulation-support treatment.

Can you ovulate if you have PMOS (PCOS)?

Yes, having PMOS doesn’t mean you never ovulate. What it commonly causes is ovulatory dysfunction. This means ovulation may happen less often, less predictably or not at all during some cycles, which is why periods can be irregular or absent and why you can sometimes have a bleed without having released an egg.

But there’s a lot of variation.You might ovulate most months but on different cycle days. Or you may have some cycles where ovulation doesn’t happen, known as an anovulatory cycle.

Not sure whether PMOS (or something else) is behind your irregular cycles? Hertility’s Advanced Hormone & Fertility Test looks at the hormones involved including LH, FSH, AMH, testosterone, prolactin and thyroid to help explain what’s driving your pattern.

Why is ovulation harder to track with PMOS (PCOS) ?

Two things make it trickier. First, cycles are often long or irregular and less predictable.  Most tracking methods and apps assume ovulation lands mid-cycle, roughly two weeks before your period, but with PMOS the follicular phase (the first half, before ovulation) can stretch out or vary a lot month to month, so ovulation can happen late, early, or not at all. It’s also why the textbook idea that everyone ovulates on day 14 really doesn’t work.

Second, and most importantly for tracking, your baseline hormones may already be raised. Many people with PMOS have persistently high LH, which is exactly the hormone home ovulation kits measure and exactly why those kits so often mislead. More on that next.

How do I know if I’m ovulating with PMOS (PCOS) ?

There isn’t one perfect at-home test. Instead, it can help to combine information that suggests ovulation might be approaching with information that tells you it probably already happened.

1. Watch your cervical mucus. In the days before ovulation, cervical mucus usually becomes wetter, clearer and more stretchy (like raw egg white) as oestrogen rises. These changes create an environment that helps sperm survive and travel through the reproductive tract, so they can be a useful sign that your fertile window may be approaching. With PMOS, fluctuating hormones can sometimes mean you notice fertile-looking mucus more than once during a long cycle. So think of cervical mucus as another piece of information rather than confirmation that ovulation definitely happened.

2. Track your basal body temperature (BBT). Progesterone causes a small rise in your resting temperature after ovulation, so charting BBT over a few cycles can confirm, in hindsight, that ovulation likely happened and reveal whether you’re ovulating at all. What it can’t do is give you any warning, by the time your temperature rises, ovulation has already been and gone. It’s also easily thrown off by poor sleep, waking at different times, illness, alcohol, travel and shift work, and long cycles can make the pattern harder to read. ASRM describes BBT as inexpensive but often unreliable, and doesn’t recommend it routinely for evaluating ovulation. So if you enjoy charting it and your pattern is clear, it’s a good piece of the picture, just don’t feel you have to wake up to a thermometer every morning to understand your fertility.

3. Track your cycles. Period tracking apps are useful for recording, less so for predicting. Most basic cycle apps estimate your fertile window from your previous period dates and average cycle length. If your cycles are fairly consistent, that gives a rough idea of when ovulation might happen, but if you have PMOS and your cycles vary a lot, the app is essentially trying to predict an unpredictable event from past averages, and calendar-based prediction is known to do this poorly. Research has found that calendar-based apps can perform poorly at identifying the actual day of ovulation because fertile-window timing naturally varies between cycles.

That doesn’t make your app useless. It’s genuinely helpful for logging things like the first day of your period, period and cycle length, flow, cervical mucus changes, ovulation-test results and symptoms. Think of it as a record of what your body has done, rather than a crystal ball for what it’ll do next.

Do ovulation predictor kits work with PMOS (PCOS) ?

Often, no, or at least not reliably. OPKs measure Luteinizing Hormone (LH) in your urine. They’re designed to detect the LH surge that typically happens 24-36 hours before ovulation. But with PMOS that baseline is frequently already elevated, and some people have several small LH rises across a cycle rather than one clean peak.

That leads to two problems. The kit can read your already-high LH as a surge and show repeated positives even when no egg is released or several apparent surges during one cycle. Or a genuine surge can be too small to stand out against a high baseline, so you miss it entirely. The issue is that most OPKs work on fixed thresholds rather than measuring your actual hormone level, fine if your levels sit in the average range, less so if PMOS keeps yours unusually high. Different brands can even have different thresholds and give you different results and either way, no OPK confirms ovulation actually happened, it only flags a likely fertile window.

None of this means throwing the kits away. If you use them, fertility specialists suggest choosing a kit with a threshold set well above your baseline, or better a quantitative test or monitor that shows your actual LH level rather than a simple positive/negative. They’re most useful paired with a method that confirms ovulation after the fact. And if you repeatedly get positives without any sign of ovulation, or never seem to catch a surge at all, that’s worth discussing with a specialist rather than testing indefinitely.

What is the best way to confirm ovulation with PMOS (PCOS) ?

A progesterone blood test. This is the most dependable way to confirm ovulation actually occurred, because progesterone only rises meaningfully after an egg is released. After ovulation, the follicle that released the egg becomes the corpus luteum, which makes progesterone. A rise in progesterone therefore provides evidence that ovulation has recently occurred.

When should you do a progesterone test if you have PCOS?

You might have heard of a day 21 progesterone test. The principle is that progesterone peaks in the mid-luteal phase, about seven days after ovulation and roughly seven days before your next period. So day 21 is only right for a 28-day cycle; if your cycle is 35 days, the right day is closer to day 28; if 24 days, closer to day 17. The luteal phase (after ovulation) is fairly consistent at around two weeks, so counting back seven days from your expected period is more reliable than counting forwards from your last one. ASRM’s 2021 committee opinion states that a mid-luteal serum progesterone concentration above 3 ng/mL (9.5 nmol/L) provides presumptive and sufficient evidence of recent ovulation.

But if your cycles are so irregular that you can’t predict your next period, that back-count doesn’t work either. In that situation, the practical approach and what many doctors advise is to test weekly until your period arrives, so you don’t miss the window. A rise confirms ovulation happened that cycle; consistently low results across cycles suggest you may not be ovulating, and are worth investigating. Because timing is so easily thrown off with PMOS, this is one area where it’s genuinely worth getting a doctor’s help rather than guessing.

Ultrasound follicle tracking. Ultrasound can give doctors a more direct picture of what your ovaries are doing. An internal transvaginal ultrasound can show developing follicles and may provide evidence that ovulation has happened, this is sometimes called follicular monitoring.

It isn’t something you need every month simply because you have PMOS. It’s more commonly used during fertility treatment or ovulation induction, where doctors may need to monitor follicle growth and how the ovaries are responding.

What if you’re trying to get pregnant with PMOS (PCOS) ?

If you’re trying for a baby, it’s very understandable to want to identify the exact day you ovulate. But if your cycles are unpredictable, chasing one perfect day can become stressful and it isn’t always necessary.

For people with irregular periods, the NHS suggests having sex every two or three days throughout the cycle when trying to conceive. This increases the chance that sperm are already present if ovulation happens unexpectedly.

You can still use cervical mucus or OPKs to identify potentially fertile days. You just don’t need to time sex to one exact hour. And importantly, PMOS does not mean you can’t get pregnant.

Irregular ovulation can mean there are fewer opportunities to conceive, but some people with PMOS conceive without fertility treatment and treatments are available when ovulation needs support.

Read more in our guide to trying to conceive with PMOS (PCOS).

The important thing is that you don’t have to spend cycle after cycle trying to decode your body on your own. If tracking consistently suggests ovulation isn’t happening, getting assessed is more useful than simply adding more tracking methods.

Tips for tracking ovulation with PMOS (PCOS)

Don’t lean on OPKs alone. Standard ovulation predictor kits are built around regular cycles and average hormone levels, so they’re not the most dependable tool if you have PMOS. Cervical mucus tracking, basal body temperature and quantitative fertility monitors (the kind that show your actual LH level rather than a simple positive or negative) will usually tell you more about what your body and hormones are actually doing.

Follow the instructions properly. Whatever you’re using, a fertility monitor or a specific cervical-mucus method. Read the instructions carefully and stick to them. Small things, like testing at the right time of day, make a real difference to how accurate your results are.

Be consistent, and give it time. Gathering enough data to spot your own pattern takes a few cycles, especially when those cycles are irregular. Try to be patient and test consistently rather than expecting a clear answer in month one.

Combine methods. No single home method is fully reliable with PMOS, so using two or three together gives you a much clearer picture and means you’ll turn up to any doctor’s appointment with genuinely useful information.

Know when to bring in a professional. Sometimes tracking can only take you so far, and that’s not a failure on your part. If you’re trying to conceive and things aren’t happening, speak to your GP or a fertility specialist, they can talk you through the next steps, which for PMOS are often very effective. 

It’s worth speaking to a GP or fertility specialist if:

• your cycles are consistently longer than 35 days, very irregular, or absent
• you have other PMOS symptoms like persistent acne, excess facial or body hair, scalp hair thinning, alongside irregular periods
• you have gone more than 3 months without a period
• you’re struggling to work out whether you ovulate at all 
• ovulation tests and tracking consistently suggest you’re not ovulating 
• your usual cycle pattern has changed significantly.

Current NICE guidance recommends referral for specialist fertility consultation after a year of trying if you are under 35, but advises seeing a doctor earlier if you are 36 or over and where there is a known clinical cause or factor that may affect fertility. So if you already know you have PMOS with irregular or absent ovulation, it’s reasonable to ask for advice earlier rather than assuming you must wait a full year.

Could something other than PMOS be affecting your ovulation?

Yes. PMOS is a common cause of irregular ovulation, but it isn’t the only one. Other factors that can affect ovulation include thyroid problems, raised prolactin, changes in weight or energy intake, intense exercise  without adequate fueling , pregnancy or breastfeeding, perimenopause, primary ovarian insufficiency (a condition where the ovaries stop functioning before the age of 40) and some medications.

This is why irregular periods or confusing ovulation-test results shouldn’t automatically be attributed to PMOS. A specialist can help assess other possible causes and decide whether further testing is needed.

Understand the hormones behind your cycle with Hertility

If your cycles are irregular, your ovulation tests never seem to make sense or you have symptoms that could point towards PMOS, Hertility can help you look at the bigger picture.

Our Advanced Hormone & Fertility Test is personalised to you and can analyse up to 10 hormones, depending on your symptoms and health history.

Depending on your personalised panel, this can include markers involved in menstrual cycles and ovulation such as LH, FSH, oestradiol and prolactin, alongside androgen and thyroid markers that may help investigate why your periods are irregular.

Rather than looking at one hormone result in isolation, Hertility considers your symptoms, menstrual cycle, medical history and hormone results together.

The Advanced Test also includes a call with a Hertility expert, so you can talk through your results and what your next steps might be. And if further investigation to confirm ovulation is appropriate, our specialists can help you understand what testing and timing might be useful.

Not sure where to start? Hertility’s Online Health Assessment uses your symptoms, periods and health history to personalise your next steps.

Ovulation and PMOS FAQs

Can you ovulate with PCOS?
Yes. Many people with PMOS ovulate, just less regularly or predictably than average. Ovulation may happen later in the cycle, vary from month to month, or be skipped in some cycles altogether. 

Why is my ovulation test always positive with PcOS?
Because PMOS often keeps LH ( the hormone ovulation kits detect ) elevated across the whole cycle, or produces several small LH rises. The kit reads that raised LH as a surge and shows a positive, even when no egg is released. It’s a known limitation of standard kits with PMOS, not a sign you’re constantly ovulating.

Can you get pregnant with PCOS?
Yes. PMOS is one of the most common causes of difficulty conceiving, but it’s also one of the most treatable. Many people conceive naturally, and where ovulation support is needed, treatments like letrozole are effective first-line options. Being diagnosed with PMOS doesn’t mean you can’t get pregnant.

When should I take a progesterone test if my cycle is irregular?
Aim for the mid-luteal phase, about seven days before your expected period, which is why counting back from your next period works better than forward from your last. If your cycle is too irregular to predict, a clinician may suggest testing progesterone weekly until your period starts so the window isn’t missed.

Does PCOS mean I’ll never ovulate on my own?
No. Some people with PMOS ovulate irregularly on their own, and lifestyle changes or treating underlying factors like insulin resistance can help restore more regular ovulation for some. Whether and how often you ovulate varies a lot from person to person, a Hertility Advanced Hormone & Fertility Test is personalised to you and can analyse up to 10 hormones, depending on your symptoms and health history. Depending on your personalised panel, this can include markers involved in menstrual cycles and ovulation such as LH, FSH, oestradiol and prolactin, alongside androgen and thyroid markers that may help investigate why your periods are irregular.

References

• Teede HJ, Tay CT, Laven J, et al. Recommendations from the 2023 International Evidence-based Guideline for the Assessment and Management of Polycystic Ovary Syndrome. J Clin Endocrinol Metab / Fertil Steril / Hum Reprod. 2023. https://doi.org/10.1210/clinem/dgad463
• Monash University / International PCOS Network. 2023 International Evidence-based Guideline for the Assessment and Management of PCOS — summary. https://www.monash.edu/medicine/mchri/pcos/guideline
• Royal College of Obstetricians & Gynaecologists / NHS laboratory guidance. Mid-luteal (day 21) progesterone testing for ovulation.
• Bull JR, Rowland SP, Berglund Scherwitzl E, et al. Real-world menstrual cycle characteristics of more than 600,000 menstrual cycles. npj Digital Medicine. 2019;2:83. https://doi.org/10.1038/s41746-019-0152-7
• NHS. Polycystic ovary syndrome. https://www.nhs.uk/conditions/polycystic-ovary-syndrome-pcos/
• NHS. Periods and fertility in the menstrual cycle. https://www.nhs.uk/conditions/periods/fertility-in-the-menstrual-cycle/
• Practice Committee of the American Society for Reproductive Medicine (2021). Fertility evaluation of infertile women: a committee opinion. Fertility and Sterility.
• National Institute for Health and Care Excellence (2024). Fertility problems: assessment and treatment (NG257). https://www.nice.org.uk/guidance/ng257