Checking fertility starts with simple tracking methods you can do at home and, when needed, moves to blood tests and imaging that a doctor can order. Most of the process is straightforward, and the right starting point depends on your age, how long you’ve been trying, and whether you have a partner whose fertility also needs evaluation.
Professional guidelines recommend starting a formal evaluation after 12 months of trying to conceive if you’re under 35, or after 6 months if you’re 35 or older. If you’re over 40, earlier evaluation is reasonable. And if you have a known condition linked to infertility, such as endometriosis, PCOS, or a history of pelvic surgery, there’s no reason to wait at all.
Track Ovulation at Home First
Before any blood draws or clinic visits, the simplest way to check fertility is confirming that you’re ovulating. Three home methods can help.
Cervical mucus: As estrogen rises in the days before ovulation, your cervix produces mucus that becomes slippery, stretchy, and resembles raw egg whites. This “egg white” mucus signals your most fertile window. Earlier in your cycle, mucus tends to be thick, sticky, or barely noticeable. Tracking this pattern over two or three cycles gives you a reliable picture of whether your body is preparing to release an egg each month.
Basal body temperature (BBT): Your resting temperature rises by about half a degree to one full degree Fahrenheit after ovulation and stays elevated until your next period. You need a BBT thermometer and you need to take your temperature at the same time each morning before getting out of bed. A chart that shows a clear temperature shift each cycle (called a biphasic pattern) confirms ovulation is happening. The limitation is that BBT only confirms ovulation after it’s already occurred, so it’s better for pattern recognition over multiple cycles than for timing sex in a single cycle.
Ovulation predictor kits (OPKs): These urine test strips detect the surge of luteinizing hormone that triggers egg release. A positive result means ovulation is likely within 24 to 36 hours, making these the most useful tool for timing intercourse. They’re available at any pharmacy without a prescription.
If all three methods consistently show you’re ovulating and you’ve been timing intercourse well, the next step is lab testing to look deeper.
Blood Tests for Ovarian Reserve
Ovarian reserve testing estimates how many eggs you have remaining. It doesn’t tell you whether those eggs are healthy or whether you’ll get pregnant, but it helps predict how your ovaries would respond to fertility treatment and gives a general picture of your reproductive timeline.
Anti-Mullerian Hormone (AMH): AMH is produced by the small follicles in your ovaries and reflects the size of your remaining egg supply. It can be drawn on any day of your cycle. Values between 1.0 and 3.5 ng/mL are generally considered normal. Below 1.0 ng/mL is considered low, though research from the EAGER trial found that women with AMH below 1.0 had similar cumulative pregnancy rates to women with normal values when trying to conceive naturally. Extremely low AMH (below 0.16 ng/mL) is more concerning, particularly for IVF, where about 54% of cycles at that level are canceled due to poor response.
FSH (Follicle Stimulating Hormone): FSH is drawn on day 2 or 3 of your menstrual cycle. Your brain produces more FSH when your ovaries aren’t responding as strongly, so a higher number can signal diminished reserve. Values above 10 IU/L are considered elevated. Like AMH, though, elevated FSH alone doesn’t predict whether you’ll conceive naturally. It becomes more meaningful when combined with other results.
Estradiol: This is often drawn alongside FSH on cycle day 2 or 3. If FSH looks normal but estradiol is elevated (above 60 to 80 pg/mL), it can mask a high FSH and still suggest the ovaries are starting to decline.
One important caveat: the American Society for Reproductive Medicine notes that ovarian reserve tests are poor predictors of reproductive potential independent from age. A 28-year-old with low AMH has a very different outlook than a 41-year-old with low AMH. These numbers are most useful in context.
How Age Affects the Picture
Age is the single strongest predictor of fertility, and no blood test overrides it. A healthy, fertile 30-year-old has roughly a 20% chance of conceiving in any given cycle. By 40, that drops to less than 5% per cycle. The decline isn’t just about egg quantity. Egg quality, meaning the likelihood that an egg will have the right number of chromosomes after fertilization, drops significantly in the late 30s and accelerates after 40.
This is why the testing timeline shifts at 35. It’s not that 35 is a cliff, but the pace of decline picks up enough that waiting a full year before investigating costs more reproductive time.
Checking the Fallopian Tubes and Uterus
Even with good eggs and regular ovulation, conception requires open fallopian tubes and a uterine cavity that can support implantation. Two imaging tests evaluate these structures.
Hysterosalpingogram (HSG): This is the standard test for tubal patency. A radiologist or reproductive endocrinologist threads a thin catheter through your cervix and injects contrast dye while taking X-ray images. If the dye flows freely through both tubes and spills out the ends, the tubes are open. The procedure takes about 10 to 15 minutes and can cause cramping similar to menstrual cramps. Some women find it mildly uncomfortable, others find it quite painful, but it’s over quickly.
Saline infusion sonohysterography (SHG): This uses saline and ultrasound rather than dye and X-rays. It’s better than HSG at detecting abnormalities inside the uterus, such as polyps, fibroids, or scar tissue, but HSG remains the preferred tool for evaluating whether the tubes are open. Your doctor may order one or both depending on what they suspect.
Don’t Skip the Semen Analysis
Male factors contribute to about half of all infertility cases, and a semen analysis is one of the simplest, least invasive tests in the entire workup. It should be done early, not as a last resort after months of testing the female partner.
The test requires a semen sample, usually collected at a lab or at home with a provided container and a short delivery window. The lab evaluates several parameters against reference values established by the World Health Organization. The key benchmarks from the most recent (2021) WHO manual include a total sperm count of at least 39 million per ejaculate, total motility of at least 42% (meaning that percentage of sperm are moving), and at least 4% normal morphology (the percentage of sperm with a typical shape).
Falling below one of these thresholds doesn’t necessarily mean pregnancy is impossible. These are fifth-percentile cutoffs, meaning 95% of men who recently fathered a child scored above them. But consistently low numbers across a repeat test point toward a male factor that needs treatment or assisted reproduction.
Hormone Tests Beyond Ovarian Reserve
Depending on your symptoms and history, your doctor may check additional hormones that affect fertility indirectly.
- Thyroid hormones (TSH): Both overactive and underactive thyroid function can disrupt ovulation and increase miscarriage risk. This is a simple blood draw and easily treatable if abnormal.
- Prolactin: Elevated prolactin can suppress ovulation. High levels sometimes cause milky nipple discharge or irregular periods, but not always.
- Androgens (testosterone, DHEA-S): Elevated levels may suggest PCOS, one of the most common causes of irregular ovulation.
- Progesterone: Drawn about a week after suspected ovulation (around cycle day 21 in a 28-day cycle), progesterone confirms whether ovulation actually occurred. A level above a certain threshold indicates that the ovary released an egg and is producing the hormone needed to support early pregnancy.
What the Results Actually Tell You
Fertility testing is better at identifying specific problems than at predicting success. A normal workup doesn’t guarantee quick conception, and an abnormal result doesn’t mean pregnancy is off the table. Roughly 15 to 30% of couples who complete a full evaluation receive a diagnosis of “unexplained infertility,” meaning all tests come back normal but pregnancy still hasn’t happened.
What testing does well is rule out treatable barriers. Blocked tubes, low sperm count, thyroid dysfunction, and anovulation all have clear treatment paths. Finding these problems early avoids months of trying with an obstacle that could have been addressed.
If you’re just starting to think about fertility and aren’t actively trying yet, AMH and a basic hormone panel can give you a general sense of your ovarian reserve. Some clinics offer these as standalone “fertility awareness” panels. Just keep in mind that reassuring results don’t guarantee future fertility, and concerning results don’t mean you’re out of time. They’re one data point alongside the most important variable: your age.