How Long Does Ovulation Last?

If you're trying to get pregnant (or trying not to), it's key to know when you're ovulating. That's because having sex just before and during ovulation—overlapping with your six-day "fertile window"—gives you the best chance at conception.

Here's what to know about how long ovulation lasts, so you can effectively track your fertility and plan your baby-making sex.

What Is Ovulation?

During ovulation, a mature egg is released from the ovaries and travels down the fallopian tube. It survives for 12-24 hours, then it disintegrates into the uterine lining and eventually sheds with the monthly period. However, if sperm fertilizes the egg before it disintegrates, it may attach to the uterine lining and form a pregnancy.

Sperm can survive in the female reproductive tract for up to five days. Therefore "someone can get pregnant from an act of intercourse anywhere from five days prior to ovulation to 24 hours after ovulation," since the egg lives for 24 hours, says Staci Pollack, MD, MS, an OB-GYN with the Montefiore Medical Center.

Timing sex during this six-day "fertile window" makes you significantly more likely to get pregnant.

When Does Ovulation Happen?

To know how long ovulation lasts, it helps to understand when it occurs. In general, people ovulate approximately 14 days before their menstrual period, says Sharifa Menon, MD, FACOG, an OB-GYN at Westchester Medical Center.

For example, a person with a cycle lasting 28 days will likely ovulate on day 14. Similarly, if someone's cycle lasts 30 days, ovulation will probably occur on day 16. Every person ovulates differently though, so take these guidelines with a grain of salt.

How to Track Ovulation

There are many methods of tracking and predicting ovulation so you can figure out when you're most fertile, including the following:

• Online ovulation calculators
• Ovulation predictor kits (these detect a rise in LH that happens about 36 hours before ovulation)
• Fertility monitors
• Charting your basal body temperature (it rises slightly during ovulation)
• Checking for fertile cervical mucus (it gets stretchy like egg whites during ovulation)
  
• Monitoring physical signs of ovulation

How Long Is Ovulation?

A person ovulates one time per menstrual cycle. Once the egg is released, it survives for 12 to 24 hours in the fallopian tube. It has the potential to be fertilized during this time.

That said, while ovulation only happens once per cycle, your "fertile window" (when you're most likely to conceive) spans six days. That's because sperm can survive for multiple days in the reproductive tract, so days-old sperm can fertilize a newly released egg.

When Is the Best Time to Have Baby-Making Sex?

The best time to have conception sex can be hard to pinpoint. If you're trying to conceive, Dr. Pollack recommends having sex often during your six-day "fertile window," when sperm and egg have the greatest likelihood of meeting.

Your fertile window is the day of ovulation and the five days before. Here are some examples, assuming ovulation happens 14 days before the start of your next period:

• A person with a cycle lasting 28 days ovulates on day 14, and their fertile window would be days 9-14.
• A person with a 30-day cycle will probably ovulate around day 16, and their fertile window would span days 11-16.

Keep in mind that the chances of getting pregnant are especially high on the day of ovulation and three days prior.

How Do You Know If You're Not Ovulating?

There's also a chance that a person doesn't ovulate at all, which is called anovulation. It means an egg is never released during the menstrual cycle, and it's usually caused by underlying conditions like polycystic ovary syndrome (PCOS).

You can't conceive if you don't ovulate, so talk to your doctor if you're worried. Irregular periods or completely absent periods are signs that ovulation may not be occurring, or may be occurring infrequently. Not seeing fertile cervical mucus is another potential sign of anovulation. It's possible to have regular periods and not be ovulating, but this is uncommon.

You should also speak with your health care provider if you can't get pregnant after one year of trying (or after six months of trying if you're over 35 years old). They might refer you to a fertility specialist.

Additional reporting by Rachel Gurevich, RN