What You Can and Can't Test About Your Fertility

Fertility is one of those topics that most of us are taught to ignore until we’re actively trying to get pregnant. But as more women take ownership of their reproductive plans—whether through egg freezing or simply learning more about their options—there’s growing interest in testing fertility early. The promise of data is appealing: if you could find out where you stand, maybe you could make clearer decisions about your timeline, your body, and your future.

But the reality is a bit messier. Yes, there are ways to test aspects of your fertility. But there’s also a lot that can’t be measured—at least not with the kind of certainty many people expect. Some tests give useful insights. Others are often misunderstood. And some questions still don’t have reliable answers, no matter how many labs you send your blood to.

In this article, we break down what you can and can’t learn about your fertility from today’s most common tests, especially if you’re in your 20s and thinking about options like egg freezing. We’ll also cover how to think about those results, what they actually mean for your future fertility, and what they don’t tell you.

You can test your ovarian reserve

Let’s start with the most talked-about test: Anti-Müllerian Hormone (AMH). This is a hormone produced by small follicles in your ovaries. The more of these follicles you have, the higher your AMH level tends to be. That makes it a useful proxy for ovarian reserve, or the estimated number of eggs you have left.

AMH will not tell you the exact number of eggs you have remaining, but it can be used to reliably predict how you’ll respond to fertility treatment. If you’re considering egg freezing, for example, a high AMH might suggest you’ll produce more eggs during a stimulation cycle, which could mean fewer cycles overall. A lower AMH might signal the opposite.

That said, AMH doesn’t predict whether you can get pregnant unassisted. It also doesn’t reflect egg quality. Many people with low AMH conceive without issues, and many people with high AMH still face fertility struggles.

In short: AMH is helpful for understanding how your ovaries might respond to medication, but it’s not a fertility report card. It’s a piece of the puzzle, not the whole picture.

You can check your follicle count, but it varies

Another test used to assess ovarian reserve is the antral follicle count (AFC), which is done via vaginal ultrasound. AFC is the number of small follicles in your ovaries that are visible on an ultrasound at the start of your menstrual cycle.

• Antral = fluid-filled, early-stage follicles
• Follicle = a tiny sac that contains an immature egg
• Count = how many are seen on the scan

AFC gives your doctor an idea of how many eggs your ovaries might be able to produce that month and helps estimate your overall ovarian reserve. Like AMH, this gives a snapshot of the eggs your body might recruit that month.

A higher count usually means a better response to egg freezing medications. It can also confirm whether your AMH results are in line with what your ovaries are actually doing.

But this test depends a lot on timing and technique. Different providers might get slightly different counts, and the number can fluctuate month to month. So while it’s useful when paired with other data, it’s not always consistent on its own.

You can evaluate your hormone levels, but they’re not always predictive

In addition to AMH, your provider may check other hormone levels at the start of your cycle (It is especially important that FSH and E2 are tested in the early follicular phase, as they cannot be reliably interpreted if done at a random phase of the cycle):

• FSH (follicle-stimulating hormone): Higher levels can suggest your ovaries are working harder to produce eggs, which may point to lower ovarian reserve.
• Estradiol (E2): This form of estrogen is measured alongside FSH to interpret the results accurately.
• LH (luteinizing hormone) and TSH (thyroid-stimulating hormone): These are sometimes included to rule out other hormonal conditions.

These blood tests are relatively easy to obtain and often included in a fertility workup. But their meaning can vary depending on when they’re taken and your cycle regularity. Like AMH, they don’t offer a yes-or-no answer about whether you’re fertile, they just add context.

There’s no test for egg quality 

This is where things get tricky. While you can estimate how many eggs you might have, there’s no current test that can measure the quality of your eggs. Egg quality mostly refers to whether an egg has the correct number of chromosomes. As people age, their eggs are more likely to develop abnormalities that make fertilization or a healthy pregnancy less likely.

Right now, the only way to assess egg quality is by making embryos. But even then, it’s difficult to know if the quality issue is from the egg, sperm, or a combination of both. 

Statistically speaking, younger people are more likely to have higher-quality eggs. But that’s a generalization, not a guarantee. Two people the same age can have different egg quality, and there’s no blood test that can measure this with accuracy.

So when people say, “Your egg quality declines with age,” they’re right. But when someone says, “You can test your egg quality,” they’re overselling it.

You can’t test how long you’ll be fertile

This is another common misconception. You might think that by testing your AMH or other hormones, you can predict how many fertile years you have left. Unfortunately, fertility doesn’t follow a strict countdown clock.

AMH gives a rough estimate of ovarian reserve, but it can’t tell you exactly when you’ll hit menopause, or when your eggs will stop being viable. Some people with high AMH experience early menopause. Others with low AMH get pregnant without issue. There’s too much individual variation to make long-term predictions with confidence.

Egg freezing can give you more options in the future—but it’s not a guarantee. The number and quality of frozen eggs, your age at the time of freezing, and your overall health all factor into how likely those eggs are to result in a baby later.

You can assess whether your fallopian tubes are clear

One test that often gets less attention in fertility conversations—but can be important—is the hysterosalpingogram (HSG). This is a specialized X-ray that looks at the inside of the uterus and fallopian tubes. It’s typically done by injecting a dye through the cervix and using imaging to see how the dye moves through the reproductive tract.

The goal is to check whether there are any blockages or structural issues that could prevent sperm and egg from meeting. If the dye flows freely through the fallopian tubes and into the abdominal cavity, that’s a good sign. If it doesn’t, it could indicate a blockage that might affect natural conception.

An HSG doesn’t give information about eggs, hormones, or ovulation, but it does offer a window into the physical pathways that make pregnancy possible. If you’ve had pelvic infections, endometriosis, or abdominal surgery in the past, your doctor may recommend this test as part of your fertility workup.

What about at-home fertility tests?

You’ve probably seen ads for at-home fertility tests promising insights into your reproductive future. Most of these kits check AMH, and some also offer hormone panels that include FSH, LH, and estradiol.

These can be helpful for getting started, especially if you’re not ready to visit a fertility clinic. But they’re not a substitute for a full medical evaluation. They also shouldn’t be used to make major decisions in isolation. If a test shows low AMH, it doesn’t mean you can’t get pregnant. And if it shows high AMH, it doesn’t mean you’re off the hook for thinking about fertility down the line.

Think of these kits as entry points—tools to start a conversation with a qualified provider, not definitive answers.

So what should you do with this information?

If you’re in your 20s, you’re in a good position to be proactive. Even though you can’t test everything, there’s value in learning what you can and starting the conversation early.

AMH and AFC can help you understand how your body might respond to treatment. Hormone panels can uncover issues you might not be aware of. And a consultation can give you space to ask questions and make a plan that fits your goals—even if that plan is just to wait and check back in a year.

It’s okay not to have all the answers. The idea isn’t to predict your future. It’s to give yourself more room to navigate it with intention.

Final thoughts

Fertility testing has come a long way, but it still has limits. You can measure ovarian reserve, hormone levels, and follicle counts. But you can’t test egg quality, predict exactly how long you’ll be fertile, or know for sure whether you’ll get pregnant naturally.

Still, having more information can be empowering—especially if it helps you make decisions on your own timeline. Whether you’re thinking about egg freezing or just want to understand your body better, asking questions now can open more doors later.

At Cofertility, we’re here to make those conversations easier, more transparent, and less intimidating. If you're considering egg freezing and want to understand what testing can (and can't) tell you, we’re happy to help you get started.