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When does ovulation occur?

Written by:, PhD, Founder and Inventor of the Proov test — the first and only FDA-cleared test to confirm successful ovulation at home.

Let’s talk about ovulation. Ovulation is incredibly important for both your health and your fertility, but sometimes it can seem like a bit of a mystery. After all, your period tends to get all the attention — it’s hard to miss, and we are often preoccupied by the symptoms leading up to and during menstruation. 

Behind the scenes, though, ovulation is really calling the shots, dictating your fertility, and regulating the timing of your period. Ovulation comes with its own set of symptoms that are less dramatic, but once you learn how to detect ovulation, you’ll realize your cycle is so much more than just about your period! 

Keep reading to find out why ovulation is so important, when it occurs, and how to predict and confirm it to better understand your health and fertility. 

when does ovulation occur?

Keep reading to learn why ovulation is so important and when it happens!

Why does ovulation matter? 

If you’re trying to conceive, ovulation is crucial! You can’t make a baby without both a sperm and an egg, and ovulation is the release of the egg from the ovary. Without ovulation, there’s no chance at conception. 

Ovulation matters for overall health, too, even if you aren’t TTC. Your cycle can be thought of as a domino effect, with several different hormones needing to reach the right level to set off the next hormone. Ovulation is the result of these hormonal changes, and healthy, successful ovulation indicates that your hormones are likely reaching healthy levels. 

Healthy hormone levels are ultimately important for all sorts of reasons-good bone density, regulating your metabolism, and mental health, including many others.

When is ovulation in the cycle? 

In an average cycle, ovulation can be thought of as approximately the halfway point. It isn’t enough to just know your average cycle length and count, though — studies have shown that there’s a lot of natural variation around ovulation day, and mistiming intercourse by assuming when you’re ovulating can actually be a primary cause of infertility. 

So it’s important to be more precise than just “the middle of your cycle” when talking about ovulation! Specifically, ovulation occurs at the end of the follicular phase, or the first half of your cycle. During this phase, follicle stimulating hormone rises, telling the ovary to begin the maturation of several follicles, or future eggs. 

As follicles begin to grow, this triggers a rise in estrogen, which signals to the brain that ovulation can occur soon. This estrogen rise is usually several days before ovulation, opening the fertile window or the time of high fertility

At this point, one follicle will become dominant and estrogen will rise even higher, resulting in a release of luteinizing hormone from the brain. This causes the follicle to release the egg, 12-36 hours past the beginning of the LH surge. 

Overall, this process (that is, the entire follicular phase) takes on average 14-19 days. Then ovulation is over, and you’re into the luteal phase and approaching the implantation window–but that’s a story for another day. 

How to Predict Ovulation 

An average of 14-19 days is a big window for ovulation to be occurring in, and of course that’s just the average. Ovulation in a given cycle could occur earlier or later than that depending on many factors. And since sperm survive only 3-5 days, if you just try to guess when you’re ovulating (or rely on a period tracking app) you may miss it entirely. 

So how do you know? Well, remember those hormones that set off the process — FSH, estrogen, and LH? The good news is that they’re easily detectable, and you can use that information to know when your fertile window is open and when ovulation is coming soon. 

Estrogen can be detected with its urinary metabolite, E1G, in the Proov Complete kit, to open the fertile window. This indicates that ovulation is likely only a few days away.

when does ovulation occur?

You can also get a good estimate of when the fertile window is opening using cervical mucus, which becomes slippery and clear like eggwhite when estrogen is high. Or you can use kegg to help you understand your fertile window based on the electrolytes in your cervical mucus! 

Estrogen will help you get close, but to be as precise as possible (without a well-timed ultrasound, anyway), you can use LH tests like Proov Predict (or Proov Complete, which also detects LH). 

LH tests will become positive, indicating the LH surge is beginning, 12-36 hours before ovulation. This is your time of peak fertility, and is the highest likelihood of conceiving. After ovulation, the egg will live 12-24 hours, and after that you’ll have to wait to next cycle to try to conceive.  

How to Confirm Ovulation Occurred 

LH tests are a great tool, and they predict the time of ovulation pretty reliably. However, it is possible to be ovulating without having a positive LH test, and up to 10% of women may actually never have a positive LH test due to naturally low LH levels. 

That’s why it’s important to confirm ovulation, not just predict it. Predicting ovulation is important for timing intercourse properly, but in order to know if there’s even a chance of pregnancy that cycle, it’s also important to validate that ovulation occurred after the fact. 

If you never have a positive LH test, this can also help you understand if your hormone levels are healthy, and gives you a retrospective idea of when you ovulated. 

Confirming ovulation is all about the final key hormone of the cycle, progesterone. Progesterone is made after ovulation, and is reflective of how successful ovulation was. Progesterone peaks around 7-10 days after ovulation during the implantation window, and there are a few ways to make sure you’re ovulating successfully based on your progesterone levels. 

You can use basal body temperature, which rises 1-3 days after ovulation. This involves taking your temperature upon waking at the same time each morning, or using a wearable like Tempdrop. This doesn’t tell you how successful ovulation was, though, just that it happened (and approximately when). 

You can determine if ovulation was successful by testing PdG, the urinary metabolite of progesterone, with Proov Confirm, the first FDA-cleared at-home PdG test. After testing on days 7-10 after peak fertility, the Proov Insight App will help you understand what your PdG levels mean and what the next steps are! 

when does ovulation occur?

Now that you know when ovulation is, you may want to…

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