Women’s fertility can be checked through a combination of blood tests, ultrasound imaging, and at-home tracking methods. No single test gives a complete picture, so most evaluations involve several approaches that together reveal how well your ovaries, hormones, and reproductive organs are functioning. Some of these you can start at home today, while others require a clinic visit timed to specific days of your menstrual cycle.
Blood Tests and When to Take Them
Timing matters enormously with fertility bloodwork. Most key hormones are measured on day 3 of your menstrual cycle, counting from the first day of full bleeding. Getting blood drawn on the wrong day can produce misleading results.
The core hormones tested on day 3 include:
- FSH (follicle-stimulating hormone): This hormone drives egg growth in your ovaries and serves as a gauge of ovarian reserve. Normal range is 3 to 20 mIU/mL, but the lower end is better. Under 6 is considered excellent, 6 to 9 is good, 10 to 13 suggests diminished reserve, and above 13 means the ovaries are very hard to stimulate with fertility medications.
- LH (luteinizing hormone): A normal day 3 level sits below 7 mIU/mL. When LH is higher than FSH, it can be one indicator of polycystic ovary syndrome (PCOS).
- Estradiol: Normal day 3 values fall between 25 and 75 pg/mL. Lower levels within that range are actually preferable. Abnormally high estradiol on day 3 may signal a functional cyst or diminished ovarian reserve.
- AMH (anti-mullerian hormone): Unlike the others, AMH can be drawn on any day of your cycle. It’s produced by the follicles in your ovaries, so higher levels generally mean more eggs remain. Average is 1.0 to 3.0 ng/mL, low is under 1.0, and severely low is 0.4 ng/mL.
A separate blood draw happens later in your cycle to check progesterone. This is typically done about a week after ovulation (around day 21 in a 28-day cycle). Progesterone levels between 2 and 25 ng/mL during this phase confirm that ovulation actually occurred. If levels are very low, it suggests you may not have ovulated that month.
What AMH Tells You About Egg Supply
AMH has become one of the most popular fertility markers because it gives a snapshot of your remaining egg supply, and it doesn’t fluctuate much throughout your cycle. The numbers drop predictably with age. At 25, a typical AMH level is around 3.0 ng/mL. By 30, it’s closer to 2.5. At 35, it drops to about 1.5, and by 40, it hovers around 1.0 ng/mL. By 45, most women are near 0.5 ng/mL.
Here’s the critical limitation: AMH and FSH measure quantity, not quality. There is no test that directly checks egg quality. You can have a strong AMH level but still have eggs with chromosomal issues, especially as you get older. Egg quality only becomes visible once IVF treatment begins and embryos can be evaluated. So a reassuring AMH result is encouraging, but it doesn’t guarantee that conception will be easy.
Ultrasound: Counting Your Follicles
An antral follicle count (AFC) uses transvaginal ultrasound to count the small fluid-filled sacs visible in your ovaries at the start of a cycle. Each follicle potentially contains an egg. Together with AMH and FSH, the AFC gives your doctor a fuller picture of ovarian reserve. This is typically done alongside the day 3 bloodwork, so both can be completed in a single visit.
Checking for Physical Blockages
Even with healthy hormones and a good egg supply, fertility depends on clear pathways. If a fallopian tube is blocked, the egg and sperm can’t meet. A test called a hysterosalpingogram (HSG) checks for this. During the procedure, a contrast dye is injected into your uterus and fallopian tubes while X-ray images are taken. If the dye flows freely through both tubes and spills out the ends, they’re open. If the dye hits a barrier and stops, a blockage is present.
An HSG also reveals the shape and structure of the uterus. It can detect fibroids, polyps, adhesions, and structural variations like a septate or bicornuate uterus, all of which can affect implantation or pregnancy. Conditions that commonly cause tubal blockages include endometriosis, prior ectopic pregnancy, and sexually transmitted infections. The test is usually scheduled between days 7 and 10 of your cycle, after bleeding has stopped but before ovulation.
Ovulation Predictor Kits
Ovulation predictor kits (OPKs) are the most accessible at-home fertility tool. They work by detecting the surge of LH in your urine that happens about 1 to 1.5 days before ovulation. When the test line is as dark as or darker than the control line, ovulation is likely imminent. According to the FDA, these tests detect LH reliably about 9 out of 10 times when used correctly.
The key word is “correctly.” You need to test at roughly the same time each day, avoid drinking large amounts of fluid beforehand (which dilutes the sample), and start testing early enough in your cycle that you don’t miss the surge. For a 28-day cycle, starting around day 10 is typical. If your cycles are irregular, you may need to test for a longer window.
A positive OPK tells you ovulation is approaching, which is useful for timing intercourse. What it doesn’t tell you is whether your ovarian reserve is healthy, whether your tubes are open, or whether your hormone levels overall support a pregnancy.
Tracking Ovulation Without a Kit
Two free methods can give you useful signals about whether and when you’re ovulating. Neither requires any equipment beyond a thermometer.
Basal body temperature (BBT) tracking involves taking your temperature first thing every morning before getting out of bed. After ovulation, your resting temperature rises slightly and stays elevated until your next period. The shift is small, often just 0.2 to 0.5 degrees Fahrenheit, so a sensitive thermometer with two decimal places helps. The catch is that BBT only confirms ovulation after it has already happened, so it’s better for understanding your cycle patterns over several months than for predicting the best day to conceive in real time.
Cervical mucus observation is the other natural tracking method. In the days leading up to ovulation, mucus produced by the cervix increases noticeably and becomes thin, slippery, and stretchy, often compared to raw egg whites. Just after ovulation, the mucus decreases and becomes thicker and less noticeable. Recognizing this shift can help you identify your most fertile window as it’s happening, giving you a real-time signal that OPKs and BBT each miss in their own way.
At-Home Hormone Kits: What They Can and Can’t Do
Several companies now sell mail-order kits that measure fertility hormones from a finger-prick blood sample collected at home. These kits typically test FSH, estradiol, progesterone, and AMH. Some also include thyroid markers like TSH, free T3, and free T4, since thyroid dysfunction can interfere with ovulation and implantation.
These kits offer convenience and privacy, and they can flag obvious red flags worth discussing with a doctor. But clinical testing remains the gold standard. At-home tests may deliver false positives or false negatives, and user error during sample collection can affect accuracy. They also can’t perform an ultrasound follicle count or check whether your fallopian tubes are open. Think of them as a reasonable screening step, not a replacement for a full fertility workup.
Putting the Results Together
No single number defines your fertility. A woman with a slightly low AMH might conceive quickly if her tubes are clear and she’s ovulating regularly. Another woman with textbook hormone levels might struggle because of a structural issue that only an HSG would catch. The value of fertility testing is in combining multiple data points to find (or rule out) specific obstacles.
If you’re under 35 and have been trying to conceive for 12 months without success, or over 35 and have been trying for 6 months, that’s the typical threshold for starting a formal evaluation. But if you simply want to understand where you stand, there’s nothing wrong with checking sooner. Starting with cycle tracking and an AMH test gives you a baseline, and a full clinical workup fills in the rest.