Ovulation itself is a brief event. The actual release of an egg from the ovary takes only a few minutes, and once released, that egg survives for less than 24 hours. But the broader fertile window surrounding ovulation stretches across several days, which is why the answer depends on exactly what you’re asking: how long the egg lasts, how long you can get pregnant, or how long ovulation symptoms stick around.
The Egg Lives Less Than 24 Hours
Once your ovary releases an egg, it begins its journey down the fallopian tube and remains viable for fertilization for under 24 hours. The highest pregnancy rates occur when sperm meets the egg within four to six hours of release. After that narrow window closes, the unfertilized egg breaks down and is absorbed by the body.
This is why timing matters so much for conception. The egg’s short lifespan means fertilization essentially needs to happen the same day ovulation occurs, or sperm needs to already be waiting in the fallopian tube when the egg arrives.
Your Fertile Window Is About Six Days
Although the egg only lasts a day, sperm can survive inside the reproductive tract for three to five days. That means sex that happens several days before ovulation can still result in pregnancy if sperm are alive when the egg is finally released. In practical terms, your fertile window spans roughly six days: the five days leading up to ovulation plus the day of ovulation itself.
This is why people trying to conceive are often advised to have sex in the days before they expect to ovulate rather than waiting for ovulation to happen. By the time you confirm ovulation has occurred, the most fertile part of the window may already be closing.
When Ovulation Happens in Your Cycle
Ovulation typically occurs about 14 days before your period starts. That countdown from the end of your cycle is more consistent than counting forward from your last period. If your cycle runs 28 days, you likely ovulate around day 14. A shorter 21-day cycle means ovulation around day 7, while a longer 35-day cycle pushes it to around day 21.
The trigger for ovulation is a surge in luteinizing hormone (LH), the same hormone detected by ovulation predictor kits. Ovulation happens roughly 28 to 36 hours after this surge begins, or 8 to 20 hours after it peaks. So a positive ovulation test tells you the egg is coming soon, not that it has already been released.
How Long Ovulation Symptoms Last
Several physical signs mark the days around ovulation, and they each follow their own timeline.
Cervical mucus changes are one of the most noticeable signals. In the days leading up to ovulation, discharge becomes progressively wetter and more slippery, eventually resembling raw egg whites. This stretchy, clear mucus typically lasts about three to four days and indicates your most fertile phase. After ovulation, mucus dries up quickly and stays that way until your next period.
Some people feel a twinge or mild cramp on one side of the lower abdomen when the egg is released. This sensation, sometimes called mittelschmerz, can last anywhere from a few minutes to a day or two. Not everyone experiences it, and the side it occurs on can alternate between cycles.
Basal body temperature provides a retrospective marker. After ovulation, your resting temperature rises slightly, typically less than half a degree Fahrenheit, though the increase can range from 0.4°F to 1°F. When you see three consecutive days of elevated temperatures, you can assume ovulation has already passed. The temperature stays elevated for the remainder of your cycle due to progesterone produced by the structure the egg left behind on the ovary.
What Happens After the Egg Is Gone
Once ovulation occurs, the empty follicle on the ovary transforms into a temporary structure called the corpus luteum. It pumps out progesterone for about 14 days, which thickens the uterine lining and raises your body temperature. If the egg isn’t fertilized, this structure breaks down, progesterone drops, and your period begins. This second half of the cycle is remarkably consistent at around two weeks, even in people whose overall cycle length varies.
Factors That Can Delay or Disrupt Ovulation
While ovulation itself is brief, the buildup to it can be thrown off by a number of factors. Chronic stress is one of the most common culprits. Prolonged stress can block or delay the LH surge that triggers egg release, pushing ovulation later in your cycle or preventing it entirely. The same is true of significant weight loss or gain, excessive exercise, and illness.
Age also plays a role in whether ovulation happens at all. Younger women in their teens and early twenties skip ovulation more frequently than those in their thirties. In one large population study, only about 50% of women under 30 had ovulatory cycles, compared to roughly 67% of women aged 30 to 34. Ovulation rates stayed relatively stable through the late forties, then began declining again as the body approached menopause. A cycle can appear completely normal in length and still be anovulatory, meaning no egg was actually released.
If your cycles are highly irregular, very short, or very long, ovulation timing becomes harder to predict. Tracking cervical mucus, basal temperature, or using LH test strips over several months can help you identify your own pattern rather than relying on averages.