The most common signs of infertility in women include irregular or absent periods, unusually painful menstruation, and the inability to conceive after 12 months of regular, unprotected sex (or 6 months if you’re 35 or older). Some signs are obvious, while others are subtle or even silent. Here’s what to look for and what each sign can tell you about your fertility.
Irregular or Missing Periods
Your menstrual cycle is the most visible indicator of your reproductive health. A typical cycle runs about 28 days, give or take a few. If the length between your periods keeps changing significantly from month to month, that inconsistency can signal a problem with ovulation. When your body doesn’t release an egg regularly, a condition called anovulation, conception becomes much harder or impossible during those cycles.
Periods that are extremely heavy (losing more than about 16 teaspoons of blood per cycle or bleeding longer than seven days) also deserve attention. So do periods that suddenly become very light or disappear altogether. Any of these patterns can point to hormonal imbalances, thyroid problems, or structural issues that affect fertility.
Physical Signs of Hormonal Imbalance
Polycystic ovary syndrome (PCOS) is one of the most common causes of female infertility, and it often announces itself through visible changes in your body well before you start trying to conceive. Up to 70% of women with PCOS develop excess hair growth on the face, arms, chest, or abdomen. Persistent acne on the back, chest, and face that doesn’t respond well to typical treatments is another hallmark, often continuing long past the teenage years.
Weight is also part of the picture. Between 40% and 80% of women with PCOS have obesity and find it unusually difficult to maintain a healthy weight. If you’re noticing a combination of these symptoms, especially alongside irregular periods, PCOS is worth investigating. It disrupts ovulation, but it’s also one of the most treatable causes of infertility once identified.
Pelvic Pain That Goes Beyond Normal Cramps
Most women experience some cramping during their period. But pain that is significantly worse than typical menstrual cramps, starts days before your period, radiates into your lower back and abdomen, and lingers well into your cycle can be a sign of endometriosis. This condition occurs when tissue similar to the uterine lining grows outside the uterus, and it directly affects fertility by causing inflammation and scarring in the reproductive organs.
Other pain patterns to watch for include pain during or after sex, and pain during bowel movements or urination that worsens around your period. These are all associated with endometriosis and can indicate damage to the areas where conception and implantation need to happen.
Unusual Discharge or Signs of Past Infection
Pelvic inflammatory disease (PID) is a bacterial infection of the reproductive tract that can cause serious, lasting damage to the fallopian tubes. The tricky part is that PID sometimes produces no noticeable symptoms at all. Some women don’t discover the damage until they struggle to get pregnant or develop chronic pelvic pain that won’t go away.
When PID does produce symptoms, they include lower belly and pelvic pain, vaginal discharge that’s heavier than usual or has a foul smell, bleeding between periods, pain during sex, and fever. Each episode of PID increases the risk of tubal scarring, and delaying treatment raises that risk further. If you’ve ever had a sexually transmitted infection or symptoms like these, even briefly, the resulting scarring could be silently affecting your fertility years later.
Changes in Cervical Mucus
Cervical mucus shifts throughout your cycle in a predictable pattern that reflects your fertility at any given time. During your most fertile window, near ovulation, mucus becomes transparent, stretchy, slippery, and resembles raw egg white. This type of mucus helps sperm travel efficiently and signals that your body is preparing to release an egg.
If you never observe this slippery, egg-white mucus during your cycle, and instead your mucus stays consistently dry, sticky, or thick, it may indicate that ovulation isn’t occurring normally. Tracking these changes over a few months can give you useful early information, though it’s not a definitive test on its own.
The Timeline That Defines Infertility
Not every difficulty getting pregnant means something is wrong, but reproductive medicine uses clear timelines to define when evaluation should begin. The American Society for Reproductive Medicine recommends that women under 35 seek evaluation after 12 months of regular, unprotected sex without conceiving. For women 35 and older, that window shortens to 6 months. For women over 40, even more immediate evaluation may be appropriate.
These aren’t arbitrary cutoffs. They reflect the reality that egg quantity and quality decline with age. A blood test measuring anti-Müllerian hormone (AMH) can give you a snapshot of your remaining egg supply. Typical AMH levels drop steadily over time: around 3.0 ng/mL at age 25, 2.5 at 30, 1.5 at 35, 1.0 at 40, and 0.5 at 45. Lower-than-expected AMH for your age doesn’t guarantee infertility, but it suggests a smaller window and may influence how aggressively you and your provider approach next steps.
When There Are No Signs at All
Perhaps the most frustrating reality is that infertility often presents with no symptoms whatsoever. Roughly 22% to 28% of all infertile couples receive a diagnosis of unexplained infertility, meaning standard testing doesn’t reveal a clear cause. This is slightly more common in women over 35 (about 26%) compared to those under 35 (about 21%). In these cases, cycles look normal, periods arrive on schedule, hormone levels test within range, and yet conception doesn’t happen.
Unexplained infertility doesn’t mean nothing is wrong. It means the cause isn’t detectable with current testing. Treatment options still exist and are often effective, but it underscores why the inability to conceive within the expected timeframe is itself the most important sign, even when everything else appears fine.
Secondary Infertility: When It Happens After a Previous Pregnancy
Having had a baby before doesn’t protect you from infertility later. Secondary infertility is the inability to get pregnant or carry a pregnancy to term after previously giving birth without fertility treatment. The same timelines apply: 12 months of trying if you’re under 35, 6 months if you’re over 35.
The signs mirror primary infertility, including irregular periods, pain, or hormonal changes, but the emotional experience often catches people off guard. Many assume that because it happened before, it should happen again. Changes since your last pregnancy, such as age-related egg decline, new hormonal conditions, weight changes, or infections, can all shift the landscape. Evaluation typically includes reviewing what’s changed since your previous pregnancy, checking hormone levels, imaging the uterus and fallopian tubes, and assessing your partner’s sperm quality.