If you have regular periods, it is a good sign that you are ovulating (releasing eggs), and that you have a chance of getting pregnant in each cycle.

Your egg is capable of being fertilised 12 to 24 hours after ovulation, which may seem like a dauntingly short time to get the egg and sperm to meet. Despite this, sperm can survive in the female genital tract for up to five days, so it is still possible to get pregnant if you have sex in the days leading up to ovulation. So learning how to detect ovulation is fundamental to increasing your chances of getting pregnant in each cycle.

Tracking your periods is a helpful starting point to understanding your cycle and 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. This means you’re likely to be fertile from day 10! But don’t forget, everyone’s cycle is unique and so finding your own rhythm is really important. Ovulation generally occurs 12 to 16 days before your next period and can vary from cycle to cycle.

If your cycles are irregular and Mother Nature likes to keep you on your toes, tracking your cycle is even more important to understanding your fertility. This information is also vital should you require help from a fertility specialist at a later date. Keeping track of your cycle for a minimum of six months will help you find your own patterns! 

If this all seems a bit confusing, don’t worry, help is at hand! You can detect ovulation using a variety of methods, which can help you pinpoint the best time to try for a baby. Not all methods will work for everyone, so it is helpful to try a few to get the best insight into your individual cycle. 

LH surge

From the start of your cycle, your estrogen levels will increase to thicken the lining of your womb in preparation for pregnancy and to create a sperm-friendly environment. When estrogen levels reach a certain point, it triggers the release of another hormone called luteinizing hormone (LH). LH is the hormone which matures your eggs in preparation for fertilisation and causes you to ovulate. This is why measuring this hormone is so useful for identifying your fertile window! 

Ovulation kits can be used to detect the levels of LH in your urine and tell you when you’re approaching ovulation. Although LH is always present at a low level, it significantly increases 24-36 hours before you ovulate. Ovulation sticks can be up to 99% accurate and so this is considered the best way to identify when you’re fertile. 

Changes in cervical mucus 

The consistency of your cervical mucus changes across your menstrual cycle. Within the fertile window, your mucus may become clear and stretchy rather than white or cloudy – a bit like egg white. This helps the sperm swim through the cervix and towards the egg. Don’t get too hung up on mucus though! The appearance of your cervical mucus can be affected by many other factors, such as infections, sex and medications, and may naturally alter within each cycle. 

Temperature rise

After you ovulate, your body temperature increases by 0.4-1°C. It is unlikely that you will be able to feel this change (you won’t get a sudden hot flush!) but this can be monitored with an accurate thermometer. To use this method effectively, it is important that you take your temperature first thing every morning before moving to get an accurate reading. Although this may be useful for some people, there are many 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 very reliable. It is also important to consider that this method will only tell you that you have ovulated, and so can’t be used to tell you when your fertile window is starting. 

Changes in saliva

Your saliva can also vary due to the hormonal changes of your cycle. High levels of estrogen will cause there to be more salt in your saliva, which can be identified through a specific patterning in a dried sample. Kits can be bought to help you do this, which usually consist of a small microscope and a glass slide for you to spit on. The pattern seen at ovulation is called “ferning” and can be quite difficult to identify. Like some of the other methods, 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 – Mittelschmerz

Ovarian pain around the time of ovulation is a fairly common symptom which is experienced by about one in five women. This can be caused by many things, including 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). As this can be caused by lots of things, it isn’t a reliable method of finding out when you have ovulated and isn’t a recommended method for tracking your fertility.  


 If you would like help to detect ovulation, or if you have any questions about your overall female health, we’d love to help you out. Our at-home hormone test can give an insight into your egg count, ovulation and highlight any red flags to do with fertility. But at Hertility, we don’t believe in giving results without the rest. Our team of experts include fertility specialists that can help you to create an actionable plan for your fertility future.