Your body gives several reliable signals that indicate whether you’re fertile during a given cycle, and there are also medical tests that can assess your overall fertility. For most people, the easiest place to start is tracking changes that happen naturally each month: shifts in cervical mucus, body temperature, and cycle regularity all offer real clues about whether ovulation is occurring.
Cervical Mucus Is the Easiest Daily Signal
The texture and appearance of your cervical mucus changes predictably throughout your cycle, and these changes are one of the most accessible ways to gauge fertility on any given day. Before ovulation, mucus is thick, white, and dry or sticky, sometimes with a paste-like consistency. As you move closer to your fertile window, it becomes creamy and smooth, similar to yogurt. Then, right before ovulation, it shifts dramatically: clear, slippery, stretchy, and resembling raw egg whites. That egg-white texture is the hallmark of peak fertility.
After ovulation passes, mucus returns to thick and dry. If you never notice that slippery, stretchy mucus at any point during your cycle, it could be a sign you’re not ovulating that month.
What Your Basal Body Temperature Tells You
Your resting body temperature rises slightly after ovulation, typically by less than half a degree Fahrenheit (about 0.3°C). The shift is small enough that you need a basal body thermometer to catch it, and you need to take your temperature first thing in the morning before getting out of bed. When that slightly higher temperature holds steady for three days or more, ovulation has likely occurred.
The catch with temperature tracking is that it confirms ovulation after the fact rather than predicting it. By the time you see the sustained rise, your fertile window for that cycle is already closing. That makes it most useful as a pattern-recognition tool over several months. If you track consistently and never see a temperature shift, that’s a signal worth paying attention to, because it may mean you’re not ovulating regularly.
Ovulation Predictor Kits Offer Advance Warning
Over-the-counter ovulation predictor kits (OPKs) detect a surge in luteinizing hormone in your urine. This hormone spikes roughly 24 to 48 hours before ovulation, so a positive test means your most fertile window is about to open. Ovulation itself typically happens 8 to 20 hours after the hormone reaches its peak.
These kits are widely available at pharmacies and are straightforward to use. Testing once or twice daily in the days leading up to expected ovulation gives you a practical heads-up that your body is gearing up to release an egg. If you use OPKs for several cycles and never get a positive result, that’s another indicator that ovulation may not be happening.
Signs That You May Not Be Ovulating
Ovulation doesn’t always happen every cycle, and some people go months without ovulating and don’t realize it. There are several patterns to watch for:
- Irregular periods. If the length of your cycle varies significantly from month to month, it suggests ovulation isn’t happening on a predictable schedule, or at all.
- Very heavy or very light periods. Losing more than about 80 mL of blood per period (soaking through a pad or tampon every hour or two) or having periods that are unusually light can both signal problems with ovulation.
- Missing periods entirely. Skipping periods when you’re not pregnant is one of the clearest signs of anovulation.
- No egg-white cervical mucus. If you monitor your mucus throughout your cycle and never see that clear, stretchy texture, your body may not be releasing an egg.
- Flat basal body temperature. No sustained temperature rise across your cycle suggests ovulation didn’t occur.
Any one of these on its own in an occasional cycle isn’t necessarily a problem. Stress, illness, travel, and weight changes can all delay or suppress ovulation temporarily. But if you notice a consistent pattern over several months, it’s worth getting a medical evaluation.
Blood Tests That Assess Overall Fertility
When self-tracking isn’t giving clear answers, or when you’ve been trying to conceive without success, blood tests can provide a more definitive picture. Two of the most common are:
AMH (Anti-Müllerian Hormone)
AMH measures your ovarian reserve, essentially how many eggs you have remaining. Average levels fall between 1.0 and 3.0 ng/mL, while levels under 1.0 ng/mL are considered low. To put those numbers in context with age: a typical 25-year-old might have an AMH around 3.0 ng/mL, a 35-year-old around 1.5 ng/mL, and a 40-year-old around 1.0 ng/mL. AMH can be drawn on any day of your cycle, which makes it convenient.
FSH (Follicle-Stimulating Hormone)
FSH is tested on day 3 of your menstrual cycle (day 1 being the first day of your period). Higher FSH levels suggest your body is working harder to stimulate the ovaries, which can indicate a declining egg supply. Research on IVF outcomes found that people with day 3 FSH levels below 15 mIU/mL had significantly better chances of pregnancy compared to those with levels between 15 and 25 mIU/mL.
Progesterone
A blood draw around day 21 of your cycle measures progesterone, which rises after ovulation. Levels above 10 ng/mL confirm that ovulation occurred that cycle. Levels below 10 ng/mL suggest either you didn’t ovulate, progesterone production was inadequate, or the test was timed incorrectly.
Fertility Isn’t Only About Ovulation
Even if you’re ovulating normally, other factors influence whether conception can happen. Blocked or damaged fallopian tubes, uterine abnormalities, thyroid conditions, and age all play a role. And roughly a third of fertility challenges involve the male partner. A semen analysis evaluates sperm count, movement, and shape. Current reference values consider at least 42% total motility and 30% progressive motility (sperm swimming forward) to be within the normal range, with a total sperm count of at least 39 million per ejaculate.
If a couple has been having regular unprotected sex and not conceiving, both partners should be evaluated rather than assuming the issue is on one side.
How Long to Try Before Seeking Help
The American Society for Reproductive Medicine recommends the following timelines for seeking a fertility evaluation. If you’re under 35, it’s reasonable to try for 12 months before getting tested. If you’re 35 or older, evaluation should begin after 6 months. For those over 40, more immediate evaluation and treatment may be warranted because egg quality and quantity decline more rapidly at that stage.
These timelines assume no known medical conditions that affect fertility. If you have a history of endometriosis, polycystic ovary syndrome, pelvic infections, cancer treatment, or other conditions linked to reproductive health, evaluation should begin right away regardless of age or how long you’ve been trying.