Gynecologic Conditions
Missed Period but Not Pregnant: 10 Common Causes
If you missed your period and you're not pregnant, the most common causes are stress, significant weight loss or gain, intense exercise, PCOS, thyroid problems, high prolactin, hormonal birth control, breastfeeding and perimenopause. An occasional late or missed period usually isn't serious. If you miss three periods in a row, or your cycle changes a lot, see a clinician.
The medical term for missed periods is amenorrhea. Most people searching this are on day 5 or day 10 of waiting, with one or two negative tests in the bathroom trash. Here's how to sort it out.
Step one: make sure you're really not pregnant
Pregnancy is still the most common cause of a missed period. Home urine tests are most accurate on or after the day your period was due, and first-morning urine is the most concentrated. If the test is negative but your period still hasn't come, repeat it in a few days to a week. A blood test at your clinician's office can detect pregnancy earlier than a home test.
A common worry: "I've taken three negative tests, could they all be wrong?" If you're well past your expected period and testing correctly, repeated negatives make pregnancy unlikely. But if your cycles are irregular, it's harder to know when you "should" have gotten your period, so one more test a week later is reasonable.
10 common causes, from most to least likely
1. Stress. Major physical or emotional stress (a move, a breakup, finals, a sick parent, a bad flu) can disrupt the signals between your brain (the hypothalamus) and your ovaries, delaying ovulation and your period. Yes, a stressful month really can do this.
2. Weight loss or not eating enough. Losing a significant amount of weight, eating too little for your activity level or having an eating disorder can make your brain "turn down" reproductive hormones. This is called functional hypothalamic amenorrhea.
3. Intense exercise. Training hard, especially in endurance sports, dance or gymnastics, without enough calories can stop periods. In athletes, missed periods can also be linked to low bone density, so they're not a badge of fitness to ignore. Marathon training season is a classic time for this.
4. Polycystic ovary syndrome (PCOS). A common cause of irregular or missing periods, often with acne, extra facial or body hair or weight gain. More in our guide to PCOS symptoms and diagnosis.
5. Thyroid problems. Both an underactive thyroid (hypothyroidism) and an overactive thyroid (hyperthyroidism) can cause irregular or missed periods. A simple blood test checks this.
6. High prolactin. Prolactin is the hormone that makes breast milk. High levels, from a small pituitary growth or certain medicines, can stop periods. You might notice milky discharge from your nipples, which people often feel awkward mentioning. Mention it.
7. Hormonal birth control. The hormonal IUD, implant, shot and continuous-use pills often make periods lighter or stop them. That's expected and not harmful. After stopping some methods, especially the shot, it can take a while for periods to return.
8. Breastfeeding. Breastfeeding can delay the return of your period after birth. You can still get pregnant before that first period shows up.
9. Perimenopause. In the years before menopause, usually in your 40s, periods often get irregular and may be skipped. Menopause is confirmed after 12 months in a row without a period.
10. Primary ovarian insufficiency and other causes. Less commonly, the ovaries stop working normally before age 40 (primary ovarian insufficiency). Other causes include scarring inside the uterus after surgery (Asherman syndrome), certain medicines such as some antipsychotics, chronic illnesses and, rarely, problems with the pituitary gland.
Clues that point to a cause
| Clue | Possible cause |
|---|---|
| Recent big stress, weight loss or heavy training | Functional hypothalamic amenorrhea |
| Acne, extra hair growth, long-standing irregular cycles | PCOS |
| Fatigue, feeling cold or hot, weight change, hair changes | Thyroid problem |
| Milky nipple discharge, headaches, vision changes | High prolactin |
| Age 40s, hot flashes, sleep problems | Perimenopause |
| Hot flashes or vaginal dryness before age 40 | Primary ovarian insufficiency |
| Recent D&C or uterine surgery | Uterine scarring |
What to do while you wait for an appointment
- Track your cycle. Write down period dates, or use an app. Note spotting, symptoms and life changes like a new job, travel, illness or a change in exercise.
- Repeat a pregnancy test if your period still hasn't come after a week or so.
- Look at your fueling. If you train hard, make sure you're eating enough to support it.
- Review your medicines and any recent birth control changes.
- Write down other symptoms: hot flashes, nipple discharge, headaches, hair growth or acne.
Don't start or stop hormonal medicines on your own to "bring on" a period without talking to a clinician.
What the visit looks like
Your clinician will ask about your cycle history, stress, diet, exercise, medicines and symptoms, and do an exam. Bring your tracking notes; they save a lot of time. Tests often include:
- Pregnancy test
- Thyroid-stimulating hormone (TSH)
- Prolactin
- Follicle-stimulating hormone (FSH) and estrogen
- Testosterone, if PCOS is suspected
- Pelvic ultrasound in some cases
Most of these are one blood draw. Results usually come back within a few days.
How it's treated
Treatment depends on the cause:
- Stress, weight or exercise-related: better nutrition, adjusted training and addressing stress, often with help from a dietitian or mental health professional
- PCOS: lifestyle changes, hormonal birth control or other medicines
- Thyroid disease: thyroid medicine
- High prolactin: medicine to lower prolactin, and imaging if needed
- Primary ovarian insufficiency: hormone therapy to protect bones and heart health
Why it matters even if you're not trying to get pregnant: going many months without a period can let the uterine lining build up in some conditions, such as PCOS, and low estrogen in other conditions can weaken bones. Persistent missed periods deserve a look.
When to see a doctor
Make an appointment with a gynecologist or primary care clinician if:
- You've missed three periods in a row and used to have regular cycles, or six months if your cycles were already irregular
- You haven't had a first period by age 15
- Your cycles suddenly become very irregular
- You have milky nipple discharge, headaches or vision changes
- You have signs of PCOS, such as excess hair growth or acne
- You're under 40 and have hot flashes or night sweats
- You're worried about your eating or exercise habits
Seek urgent care if you have a missed period with severe pelvic pain, heavy bleeding, dizziness or fainting, which could signal an ectopic pregnancy.
If your periods are changing in other ways, see our guide to abnormal uterine bleeding.
Finding care in New York
A gynecologist, OB/GYN or women's health nurse practitioner can evaluate missed periods. If you're a teen or young adult, many NYC clinics offer confidential reproductive health visits. Use our provider search, browse gynecologists, or look close to home, like gynecologists in Staten Island.
Frequently asked questions
How late can a period be before I should worry?
Cycles can vary by several days. If your period is more than a week late, take a pregnancy test. If you miss three periods in a row (or six months if your cycles are usually irregular), see a clinician.
Can a pregnancy test be negative if I'm pregnant?
Yes, especially if you test very early. If your period still has not come, repeat the test in a few days to a week, or ask your clinician about a blood test.
Can stress delay your period?
Yes. Significant physical or emotional stress can affect the brain hormones that control ovulation, delaying or stopping your period.
Is it normal to miss a period while on birth control?
Lighter or missed periods are common with some methods, especially the hormonal IUD, implant, shot and continuous pills. If you have missed pills or are unsure, take a pregnancy test.
Sources
- ACOG — Abnormal Uterine Bleeding (Patient FAQ)
- ACOG — Polycystic Ovary Syndrome (PCOS) (Patient FAQ)
- ASRM — Current evaluation of amenorrhea (Practice Committee Opinion)
- MedlinePlus — Absent menstrual periods (secondary amenorrhea)
- NIH, NICHD — Amenorrhea
This article is for general education and is not medical advice. It does not replace an evaluation by a licensed clinician who knows your history. If you think you have a medical emergency, call 911.