Tag: ovulation

Ovulation is the release of a mature egg from one of your ovaries, triggered by a surge in luteinising hormone (LH). It happens once per menstrual cycle and marks the point when pregnancy is biologically possible, but it is also an indicator that your hormones are working as they should, whether or not you are trying to conceive. This guide covers everything you need to know: how ovulation happens, when it happens, what it means for your health, the myths that routinely mislead people, what the physical signs look like, and what can disrupt the process. Quick facts How does ovulation work? Ovulation is the result of a hormonal sequence that begins the moment your period starts, not something that happens in isolation mid-cycle. At the start of each menstrual cycle, the hypothalamus, a small region at the base of your brain releases gonadotropin-releasing hormone (GnRH), which signals the pituitary gland (also in the brain), to make follicle-stimulating hormone (FSH). FSH stimulates a group of follicles in the ovaries to begin developing, each one containing an immature egg.  Several follicles begin growing simultaneously, but over the following one to two weeks, one becomes dominant – larger and more developed than the rest (which are gradually reabsorbed by the body). As the dominant follicle grows, it produces rising levels of oestrogen. This oestrogen has two simultaneous effects: it thickens the lining of the uterus in preparation for a potential pregnancy, and it sends a hormonal signal back to the pituitary gland. When oestrogen reaches a peak, it triggers dramatic release of luteinising hormone – the LH surge. This surge is the direct trigger for ovulation. Within 24 to 36 hours, the dominant follicle ruptures and releases its mature egg into the fallopian tube to be fertilised. What happens next matters as much as the egg release itself. After the egg is released, the empty follicle transforms into a structure called the corpus luteum, which makes progesterone for the remainder of the cycle. Progesterone stabilises the uterine lining and supports implantation. If fertilisation does not occur, the corpus luteum breaks down, progesterone falls, and your period begins, resetting the cycle. When does ovulation start after period and how long does it last? So, does ovulation always happen on day 14? Only in the context of a textbook 28-day cycle, and even then, it’s an approximation. In reality, ovulation occurs around 12 to 16 days before your next period, not 14 days after your last one. That distinction matters, because it means ovulation timing shifts depending on your cycle length. For example, in a shorter 24-day cycle, it may occur as early as days 8 to 12. In a longer 35-day cycle, it may not happen until days 19 to 23. While day 14 is often quoted as the “average”, applying it as a universal rule is misleading. Cycle lengths vary widely between individuals and even from month to month in the same person. If you are taking birth control or hormonal contraception, you may not ovulate. These methods work primarily by suppressing ovulation and also thickening cervical mucus, making it harder for sperm to reach and fertilise an egg. It’s also important to understand where cycle variability comes from. The second half of the cycle, from ovulation to your next period (the luteal phase) tends to be relatively consistent, typically lasting around 14 days. The variation in total cycle length mostly comes from the first half (the follicular phase), which is why ovulation timing can shift. Even if you have regular cycles, ovulation isn’t perfectly predictable. Factors like stress, illness, travel, weight fluctuation, and disrupted sleep can delay ovulation by interfering with the hormonal signals that trigger it. When a period arrives later than expected, it’s usually because ovulation happened later,  not because the period itself was delayed. As for how long ovulation lasts, the process itself only takes about 12 to 24 hours. You can expect to ovulate about 8-20 hours after your LH peaks or 24-36 hours after the LH surge begins rising. What is the fertile window? Your fertile window is a six-day window during each menstrual cycle, the five days leading up to ovulation and the day of ovulation itself when you are most likely to get pregnant. An egg can only survive for 12–24 hours after ovulation, but sperm can survive for up to five days in the female reproductive tract, so if you have unprotected sex in the days before ovulation, pregnancy is still possible. Recent research has shown that the two to three days immediately before ovulation carry the highest probability of conception. In 2025, Hertility’s research team published a study that has become the largest of its kind on fertility awareness in women actively trying to conceive. Analysing responses from 97,414 women, the study found that more than 41% could not accurately identify their fertile window.  What are the signs of ovulation? Your body produces a recognisable set of physical signs and symptoms  around ovulation. Not everyone experiences all of them, but knowing what to look for is the first step in understanding your cycle. The most consistent physical sign is a change in cervical mucus. In the days before ovulation, discharge becomes increasingly clear, slippery, and stretchy, a consistency often compared to raw egg white. This mucus coincides with peak fertility and is driven by rising oestrogen. After ovulation, progesterone causes mucus to thicken and reduce. Other signs include a mild one-sided ache or twinge in the lower abdomen (mittelschmerz), a slight rise in basal body temperature (BBT) after ovulation has occurred, light mid-cycle spotting, increased libido, and breast tenderness. To know read our blog here. How can you track ovulation signs and symptoms? There are several methods you can use to track ovulation, including hormone testing kits, monitoring cervical mucus changes, tracking basal body temperature, and using a period tracking app. Each has different strengths and limitations. Ovulation predictor kits (OPKs) Ovulation predictor kits detect the LH surge in your urine […]

For many, the journey to parenthood can be a challenging process, both physically and emotionally. We’re here to help you understand the different causes of infertility, and the options available for those who need support. Quick facts: What is infertility? Infertility is defined as not being able to conceive after one year (or longer) of trying. This could be despite having regular unprotected sex with a partner, or trying using methods like artificial insemination (IUI).  There are 2 types of infertility: In the UK, as many as 1 in 7 heterosexual couples experience infertility, yet the causes are sometimes preventative, or treatable.  Causes of infertility  There can be many different reasons why you might struggle to conceive. This can include structural fertility issues, ovulation problems, underlying health conditions and hormonal imbalances. Let’s take a look at each. Ovulation issues  Anovulation, also known as the inability to ovulate, is the most common cause of infertility. Ovulation is when a mature egg is released from one of your ovaries, each month, during your menstrual cycle. The egg travels into the Fallopian tube, where it prepares to be fertilised by a sperm, before then travelling down the tube to the uterus.  When trying to conceive, ovulation is a crucial event, with the 5 days before ovulation and ovulation day itself often referred to as your ‘fertile window’.This is the time of the month when you’ll be most likely to get pregnant.  Research suggests that as many as 25% of infertility cases are caused by anovulation. Anovulation can be caused by: Another possible explanation is a problem with the egg maturation process. This means that an “immature” egg may be released from your ovaries when it is not quite ready and unable to fertilise. Underlying health conditions Polycystic ovary syndrome (PCOS) PCOS is the most common underlying condition affecting fertility. PCOS affects as many as 1 in 10 people with ovaries.  People with PCOS produce higher levels of androgen hormones, like testosterone. This can disrupt your menstrual cycle, ovulation, and balance of cycling hormones—like oestrogen, follicle-stimulating hormone and luteinising hormone (LH). As PCOS is still under-researched and misunderstood, many people are left undiagnosed and are unaware they have it until they are actively trying to conceive. This is why it’s a good idea to check in on your hormones before you start your conception journey.  Primary ovarian insufficiency (POI)  POI is when the ovaries stop working properly before the age of 40. POI is far less common than PCOS, affecting only 1 in 100 women younger than 40. Your ovaries produce oestrogen and progesterone—two cycling hormones responsible for the regulation of your menstrual cycle. When their function is disrupted, ovulation can also become disrupted or stop completely.  People with POI also have a lower ovarian reserve, meaning fewer eggs for their age. Without a sufficient amount of eggs and the correct level of hormones needed to regulate your cycle, the possibility of conceiving is reduced considerably. According to the National Infertility Association, POI can be caused by genetics, autoimmune factors, induced by chemo or radiotherapy, or it can have an unknown cause. Uterine fibroids Uterine fibroids are noncancerous tumours that affect as many as 25% of people with a uterus. They can cause symptoms such as heavy periods, intermenstrual bleeding, and pelvic pain. In some cases, depending on the location in which they grow, and whether they affect the shape of the uterus or cervix, fibroids can also cause infertility.  This is because they can block the fallopian tubes, stopping eggs from meeting sperm, or reaching the uterus for implantation. They can also get in the way of implantation if they are near the inner lining of the womb.  Despite being less common than other causes of infertility, around 5-10% of infertile women and those assigned female-at-birth are found to have uterine fibroids, with their instance being much more common in Black women.  Endometriosis Endometriosis is a common reproductive health condition that affects around 1 in 10 women and people assigned female-at-birth. With endometriosis, tissue similar to the tissue that makes up the lining of the womb starts to grow in other places, such as the ovaries and the fallopian tubes, causing lesions and scarring.   This can cause several life-altering symptoms, such as painful and heavy periods, pain during or after intercourse and pelvic pain. It is also another common cause of infertility, with research suggesting it is present in around 20-50% of infertility cases. The exact link between endometriosis and infertility is unknown. However, some theories suggest that lesions and scarring can cause structural problems with the reproductive organs and chemical changes in the lining of the uterus. Structural infertility  Structural infertility is a problem with the anatomical structure of the reproductive organs. This can include blockages, structural damage or abnormal growth in the fallopian tubes, uterus or ovaries.  Structural issues with the ovaries or fallopian tubes can prevent eggs from being released from the ovaries or stop them from moving through the fallopian tubes to reach a sperm for fertilisation.   Additionally, if the structure of your uterus is abnormal or damaged, it may prevent eggs from implanting into the endometrium (uterus lining). This is needed to create a healthy embryo and pregnancy.  Structural infertility problems can also be caused by scarring from surgery, infections, injuries, or endometriosis.  Also, the growth of noncancerous tissues such as uterine polyps on the lining of the uterus, can cause blockages. Polyps occur when additional tissue grows on your uterus. However, sometimes tissue grows elsewhere in your reproductive system potentially blocking your fallopian tubes and preventing pregnancy.  Implantation failure Other possible explanations of implantation failure are: Infections and auto-immune disorders  Untreated sexually transmitted infections (STIs) may have serious consequences for your fertility. STIs like chlamydia or gonorrhoea can cause scarring and blocking of your Fallopian tubes.  Additionally, if syphilis is left to develop, it can cause stillbirth. There are also other forms of infections of the cervix with human papillomavirus (HPV) that could cause infertility. It’s […]

Ovulation tracking can be a great way of either avoiding or planning sex during your fertile window. There are lots of ovulation detection methods, each with varying degrees of reliability. Read on to find out which could be right for you. Quick facts: What is the fertile window? The fertile window is 6 days around the midpoint of your cycle when you ovulate. It includes the 5 days before ovulation and the day after.  Ovulation is when you release an egg from one of your ovaries, and it travels down the fallopian tube to the uterus where it hopes to reach a sperm and be fertilised.  If you have regular periods, it is a good sign that you are ovulating (releasing eggs), every month. Your egg is capable of being fertilised 12 to 24 hours after ovulation but sperm can survive in the female genital tract for up to five days. So it’s possible to get pregnant if you have sex in the days leading up to ovulation. Ovulation tracking methods Lots of people choose to track ovulation, either to avoid or to plan to have sex during their fertile window. There are a few different methods available to predict your fertile window each month, but not every method will work for everyone—so it’s useful to try a few to find your fit.  Cycle tracking Tracking your periods is a helpful starting point for finding your fertile window. If your cycle is like clockwork and lasts 28 days, the chances are you’ll ovulate halfway through your cycle on day 14. Everyone’s cycle is unique and often not 28 days. It’s important to keep track of how long your cycles last, how long your periods are and any symptoms along the way. Ovulation generally occurs 11 to 16 days before your next period but this can also vary from cycle to cycle. You can use cycle tracking apps, some of which will predict your fertile window based on your previous cycle data—but these are not always 100% accurate.  Ovulation detection kits Ovulation detection kits involve a pee stick, which you use when you’re around the time in your cycle when you’re approaching ovulation. Ovulation sticks are considered the best way to identify if you are ovulating  From the start of your cycle, your oestrogen levels will increase to thicken the lining of your womb in preparation for pregnancy. When oestrogen levels reach a certain point, it signals the release of luteinizing hormone (LH), which triggers ovulation. Although LH is always present at a low level, it significantly increases 24-36 hours before you ovulate, known as the LH surge, which is what the kits detect. Changes in cervical mucus  The consistency of your cervical mucus (discharge) changes throughout your menstrual cycle. Just before ovulation, your discharge becomes clear and stretchy, a bit like egg whites. This is to help the sperm swim through the cervix and towards the egg.  Although this can be a good indicator of when you’re nearing ovulation, remember the appearance of discharge can also be affected by many other factors. This includes infections, sex and medications, and can also naturally alter within each cycle. Basal body temperate tracking After you ovulate, your basal body temperature (BBT) increases by 0.4-1°C. It is unlikely you’ll be able to feel this change, but it can be monitored with an accurate thermometer.  To use this method effectively, you must take your BBT first thing every morning before getting up, to get an accurate reading.  Again, there are lots of things that can cause your resting temperature to vary, such as sleep changes, alcohol consumption and fighting off a cold. This means using temperature changes alone may not be the most reliable. It is also important to consider that this method will only tell you that you have ovulated and won’t be able to predict your fertile window ahead of time.  Changes in saliva Your saliva can also vary throughout your cycle. High levels of oestrogen just before ovulation can cause there to be more salt in your saliva, which can be tracked using a testing kit. A specific pattern is seen in the saliva at ovulation which is called “ferning”, but this can be quite difficult to identify.  Similar to BBT tracking, saliva testing is not always reliable, as it can be easily influenced by the things you eat and drink, so shouldn’t be used alone.  Ovulation pain  Ovarian pain, also known as Mittelschmerz, is a fairly common symptom experienced by around one in five people who menstruate. Ovulation pain can be caused by stretching of the sac of fluid which contains the egg (the follicle) during its development, or by ovulation itself (when the egg is released from the follicle).  This isn’t a reliable method of fertility tracking and isn’t usually recommended as it can also vary from cycle to cycle. If you’re experiencing pain that’s disrupting your daily activities, speak to a specialist about treatment or pain relief options. Understand your cycle As ovulation is controlled by your menstrual cycle hormones, testing your hormones can give you insights into whether you’re ovulating regularly or not.  If you’re experiencing any symptoms like irregular periods, long or short cycles, it’s a good idea to get your hormones tested to understand what’s going on with your cycle hormones.  Check out our at-home Hormone & Fertility tests to find out more.