Ovulation symptoms: How can I tell when I'm ovulating?
Medically reviewed by Emily Hu, M.D., FACOG, ob-gyn
January 29, 2021
Ovulation typically happens in the middle of your menstrual cycle. You're most fertile during the three days leading up to ovulation. It can be hard to know when you're ovulating. To figure it out, you can track common ovulation symptoms such as changes in your basal body temperature, in your cervical mucus, and to your cervix.
What is ovulation?
Ovulation is when you release an egg from one of your ovaries. From the five days before ovulation through to the day that you ovulate, you're potentially fertile. But your chances of getting pregnant are highest if you have sex in the last three days of this six-day window.
When do you ovulate?
Generally, you ovulate in the middle of your menstrual cycle. If you have an average 28-day cycle, you may ovulate around day 14. However, lengths of normal cycles can vary from 21 to 35 days. Some women ovulate around the same day each cycle, but for others the timing is hard to pinpoint.
Almost all women have these three ovulation symptoms:
Changes in basal body temperature (BBT). Your BBT is your lowest body temperature in a 24-hour period. On the day after you ovulate, your BBT will go up by 0.5 to 1.0 degree Fahrenheit and stay elevated until your next period.
Changes in cervical mucus. During the few days before you ovulate and immediately after ovulation, you may notice an increase in cervical mucus and a change in its texture.
How to calculate ovulation
There's no foolproof method to predict when you'll ovulate. But here are a few ways you can estimate when it's most likely to happen, so you can try to time sex or intrauterine insemination (IUI) accordingly and boost your chances of getting pregnant.
(If that egg gets fertilized by a sperm and implants in your uterus, you're pregnant!)
Try the calendar method
If your cycle is regular – the same number of days each time – you can try the calendar method (also known as the Standard Days Method).
To estimate when you'll ovulate:
Find your expected ovulation day: To do this, count back 14 days from when you expect your next period.
Calculate your fertile window: This includes the day you ovulate and the preceding five days. So, for example, if day 1 is the first day of your period and day 28 is the day before you expect your next period, you'd be fertile on days 9 through 14.
Emphasize the last three days: You're much more likely to get pregnant during the final three days of your fertile window than during the days immediately after you ovulate. This is because your egg survives in your fallopian tube for 24 hours after ovulation. And although sperm can survive in a woman's body for up to five days, they are more likely to fertilize your egg within three days of having sex.
This method is the easiest way to estimate your fertile window, but it's not very accurate, even if you have a good idea of when your next period will start. That's because ovulation rarely happens exactly 14 days before menstruation.
In one large study of women with 28-day cycles, the day of ovulation varied from seven to 19 days before menstruation. Ovulation happened 14 days before a period only 10 percent of the time.
So you can see how it's possible to miss your fertile window altogether using this method. On the other hand, it's simple, free, and worth a try, especially if you're not in a hurry to conceive.
Use an ovulation calculator
You can use BabyCenter's Ovulation Calculator to find out which days you're likely to be fertile according to the calendar method and what your due date will be if you conceive. It's one quick and easy way to figure out how to increase your chances of getting pregnant
Use an ovulation predictor kit
Testing your hormone levels with an ovulation predictor kit (OPK) is a more dependable way to identify your fertile window, though it doesn't work perfectly for all women.
There are two kinds of kits:
Urine tests: This is the most common. The pee-on-a-stick test indicates when your level of luteinizing hormone (LH) has gone up, which usually means one of your ovaries will soon release an egg. Some tests measure the level of another hormone, estrone-3-glucuronide (E3G), that also goes up around the time of ovulation.
Saliva tests: With the saliva test, you use a microscope to spot a pattern in your dried saliva that indicates the rise in estrogen that happens in the days before ovulation.
Both types of tests show a positive result in the days before you ovulate, giving you time to plan.