You can’t know for certain whether you’re infertile without medical testing, but there are specific signs, timelines, and risk factors that signal it’s time to get evaluated. The clinical threshold is straightforward: if you’re under 35 and have been having regular, unprotected sex for 12 months without conceiving, or over 35 and have been trying for 6 months, that meets the medical definition of infertility. Before that point, though, your body often gives clues worth paying attention to.
What Your Menstrual Cycle Can Tell You
Your period is one of the most visible indicators of reproductive health. A cycle shorter than 21 days, longer than 35 days, or one that’s highly unpredictable often means you’re not ovulating regularly. Absent periods are an even stronger signal. Ovulation is the non-negotiable event in natural conception, so any pattern suggesting it isn’t happening consistently is worth investigating early, not after months of trying.
Very heavy periods or severe pelvic pain during your cycle can point to conditions like endometriosis or uterine fibroids, both of which can interfere with conception. Light or skipped periods, on the other hand, may reflect hormonal imbalances or low body weight. None of these guarantee infertility, but they’re the kind of clues your doctor will want to hear about.
Signs of PCOS and Hormonal Imbalance
Polycystic ovary syndrome is one of the most common causes of ovulatory infertility. It’s diagnosed when at least two of three features are present: excess androgen hormones, irregular or absent ovulation, and polycystic ovaries on ultrasound. The outward signs you might notice include persistent acne, thinning hair on your head, or new hair growth on your face, chest, or back. Cycles that come more than 35 days apart, or disappear entirely for months at a time, are a hallmark.
PCOS is also closely linked to insulin resistance and weight gain, particularly around the midsection. The good news is that it’s highly treatable. Weight loss alone has been shown to improve both ovulation rates and metabolic health in women with PCOS, and medications that stimulate ovulation are effective first-line treatments. If you recognize these symptoms in yourself, getting evaluated sooner rather than later gives you more options.
Physical Signs in Men
Male factors contribute to roughly half of all infertility cases, yet men often assume the issue lies with their partner. There are physical signs worth noticing. Pain, swelling, or a lump in the testicle area can indicate a varicocele, which is a swelling of the veins that drain the testicle. It’s the most common reversible cause of male infertility because it reduces both sperm count and sperm quality.
Other signals include reduced sexual desire, difficulty maintaining erections, very low ejaculate volume, or ejaculation that feels unusual (retrograde ejaculation sends semen into the bladder instead of out). Decreased facial or body hair, unexpected breast tissue growth, and loss of the sense of smell can all point to hormonal or chromosomal issues affecting sperm production. A low sperm count is defined as fewer than 15 million sperm per milliliter of semen, but the only way to know your count is through a semen analysis, which is one of the simplest and earliest tests in any fertility workup.
How Age Affects Your Chances
Age is the single biggest factor in female fertility, and the decline is steeper than most people expect. By age 40, the chance of getting pregnant in any given monthly cycle drops to around 5%. This isn’t just about egg quantity. Egg quality declines too, which increases the risk of miscarriage and chromosomal abnormalities.
A blood test called AMH (anti-Müllerian hormone) can give you a snapshot of your remaining egg supply. Average levels fall between 1.0 and 3.0 ng/mL, with anything under 1.0 considered low. To put age-related decline in perspective: a typical 30-year-old might have an AMH around 2.5 ng/mL, while a 40-year-old averages about 1.0 ng/mL. It’s important to know that AMH reflects egg count, not egg quality, and a low number doesn’t mean pregnancy is impossible. But it can reveal that your window is shorter than expected, which is useful information when making decisions about timing or egg freezing.
Lifestyle Factors That Lower Fertility
Smoking has one of the strongest documented effects on fertility. Women who smoke are more than twice as likely to miscarry, and smokers need nearly twice as many IVF cycles to conceive compared to nonsmokers. Each year a woman smokes is associated with a 9% increase in the risk of unsuccessful fertility treatment. The damage isn’t limited to women: men whose mothers smoked more than 10 cigarettes a day during pregnancy had sperm counts nearly 50% lower than men born to nonsmoking mothers.
Being significantly over or underweight also disrupts reproductive hormones. Extreme exercise, chronic stress, and rapid weight changes can all suppress ovulation, sometimes causing periods to stop entirely. These are often reversible causes of infertility, which makes them worth addressing before assuming the problem is structural or genetic.
What Fertility Testing Looks Like
If the timeline and symptoms suggest a problem, the first round of testing is usually straightforward. For women, it typically starts with blood tests to check hormone levels (including AMH and thyroid function) and an ultrasound to look at the ovaries and uterus. A procedure called an HSG, or hysterosalpingogram, uses X-ray dye to check whether the fallopian tubes are open and whether the uterus has a normal shape. Blocked tubes are a common finding, and the test takes only a few minutes.
For men, the starting point is a semen analysis, which measures sperm count, movement, and shape. It’s noninvasive and gives a clear picture of whether male factor infertility is playing a role. Doctors may also check hormone levels, particularly testosterone, if the semen analysis comes back abnormal.
These initial tests identify a cause in the majority of cases. Sometimes everything comes back normal, a situation called unexplained infertility, which accounts for a meaningful percentage of couples who struggle to conceive. That diagnosis doesn’t mean nothing is wrong. It means the current tests didn’t catch it, and treatment options still exist.
Secondary Infertility Is Equally Common
Having had a baby before doesn’t protect you from fertility problems later. Secondary infertility, the inability to get pregnant or carry a pregnancy to term after a previous birth, affects about 11% of couples in the United States, making it just as common as primary infertility. Age, new medical conditions, weight changes, and partner changes can all play a role. People experiencing secondary infertility often delay seeking help because they assume their previous pregnancy proves everything still works. The same timelines apply: 12 months of trying under 35, 6 months over 35.