Your body gives several reliable signals that ovulation is approaching or has just happened. Some are subtle enough that you need a thermometer or test strip to catch them, while others you can notice on your own once you know what to look for. The most practical signs include changes in cervical mucus, a small rise in resting body temperature, and the results of at-home urine tests that detect a hormonal surge roughly 12 to 24 hours before the egg is released.
Cervical Mucus Changes
The most accessible daily clue is the fluid your cervix produces throughout your cycle. In the days after your period, you’ll likely notice very little discharge, or it may be thick and sticky. As ovulation approaches, rising estrogen levels cause cervical mucus to become wetter, stretchier, and more slippery. At peak fertility, it looks and feels like raw egg whites: clear, stretchy between your fingers, and distinctly slippery. This consistency makes it easier for sperm to travel through the uterus.
You typically get this egg-white mucus for about three or four days. Once ovulation passes, the mucus dries up again or turns thick and pasty. Checking is straightforward: wipe before using the bathroom, or pay attention to what you see on underwear or toilet paper. Tracking these changes over two or three cycles gives you a personal pattern to compare against.
Ovulation Predictor Kits
Over-the-counter ovulation predictor kits (OPKs) work by detecting luteinizing hormone (LH) in your urine. Your brain releases a surge of LH that triggers the ovary to release an egg roughly 36 to 40 hours later. Because LH builds up in urine more slowly than in blood, a positive result on a urine test typically means ovulation will happen within 12 to 24 hours.
Most kits work like pregnancy tests: you hold a test strip in your urine stream or dip it in a collected sample. A positive result (usually a test line as dark as or darker than the control line) signals the LH surge. Testing once or twice daily starting a few days before you expect to ovulate gives you the best chance of catching the surge. If your cycles are 28 days, that usually means starting around day 10 or 11. With irregular cycles, you may need to test over a wider window.
Basal Body Temperature
Basal body temperature (BBT) is your body’s resting temperature taken first thing in the morning, before you get out of bed or even sit up. Before ovulation, most people run between 96 and 98°F (35.5 to 36.6°C). After ovulation, progesterone causes a small but measurable rise, typically less than half a degree Fahrenheit. The increase can be as little as 0.4°F or as much as 1°F, depending on the person. Your temperature stays elevated until your next period.
The catch with BBT tracking is that it confirms ovulation only after it has already happened. You won’t see the shift until the day after the egg is released, so it’s most useful for understanding your cycle pattern over several months rather than pinpointing the fertile window in real time. A regular digital thermometer works, but one that reads to two decimal places (like 97.62°F) makes it easier to spot the small shift. Illness, poor sleep, alcohol, and getting up earlier than usual can all throw off readings.
Ovulation Pain
Some people feel a twinge or cramp on one side of the lower abdomen around the time the egg is released. This is called mittelschmerz (German for “middle pain”). It can feel like a dull ache, a sharp pinch, or mild pressure, and it usually lasts anywhere from a few minutes to a few hours. In some cases it lingers for a day or two. It tends to alternate sides from month to month, depending on which ovary releases the egg.
Not everyone experiences this. Some people feel it every cycle, others only occasionally, and many never notice it at all. On its own, ovulation pain is not reliable enough to time intercourse or confirm ovulation, but it’s a helpful supporting clue when combined with other signs.
Other Body Signals
The hormonal shifts around ovulation can produce a few other changes that are less precise but still worth noticing. Some people experience mild breast tenderness, a slight increase in sex drive, or light spotting. The cervix itself changes position and texture: it moves higher, feels softer, and opens slightly around ovulation. Checking cervical position takes some practice and isn’t as immediately useful as mucus tracking, but it adds another data point if you’re charting.
Saliva-based ovulation tests are also available. Rising estrogen before ovulation can cause dried saliva to crystallize in a fern-like pattern under a small microscope. The FDA notes that these tests aren’t especially reliable. You can sometimes see ferning outside your fertile window or during pregnancy, so the results are harder to interpret than urine-based LH tests.
How Doctors Confirm Ovulation
If you’re working with a doctor, they can confirm ovulation with a blood test measuring progesterone. After the egg is released, progesterone rises significantly. A blood draw timed about a week after suspected ovulation (around day 21 of a 28-day cycle) shows whether the rise occurred. Ultrasound can also track a developing follicle in the ovary and confirm its release, though this is typically reserved for fertility treatment rather than routine checking.
Putting the Signs Together
No single sign is perfectly reliable on its own. The most effective approach combines two or more methods: tracking cervical mucus daily for a real-time signal, using an OPK to catch the LH surge, and logging BBT to confirm ovulation after the fact. Over two or three cycles, a pattern usually emerges that makes your fertile window predictable.
Your fertile window is wider than the moment of ovulation itself. Sperm can survive in the reproductive tract for three to five days, so the days leading up to ovulation are just as important as ovulation day. If you’re trying to conceive, having intercourse in the days when you notice egg-white mucus or get a positive OPK gives you the broadest coverage. If you’re trying to avoid pregnancy, keep in mind that these tracking methods have higher failure rates than hormonal contraception and require consistent, careful use.