A missed period with a negative pregnancy test is common and often caused by stress, weight change, intense exercise, hormonal contraception, PCOS, thyroid problems, breastfeeding or approaching menopause. If your period is more than a week late, repeat the pregnancy test; if periods stop for three months or more, see a doctor.
12 common reasons
- Stress: exams, work pressure, relocation or grief can delay ovulation
- Weight loss or low body weight
- Weight gain or obesity
- Intense exercise, especially with low calorie intake
- Polycystic ovary syndrome (PCOS)
- Thyroid problems (overactive or underactive)
- Hormonal contraception (pill, implant, injection, hormonal IUD), or stopping it
- Breastfeeding
- Perimenopause
- Shift work and travel across time zones disrupting body clock
- Medicines: some antipsychotics, antidepressants, steroids, chemotherapy
- High prolactin or other hormone conditions
Could I still be pregnant?
A test taken too early can be negative. Repeat it a week later using first-morning urine. If periods remain absent and you’ve had unprotected sex, test again.
When to see a doctor
- No period for 3 months (or longer than your usual cycle × 3)
- Periods stop before age 45
- Repeated negative tests but symptoms of pregnancy
- Excess hair growth, acne or weight gain (possible PCOS)
- Milky discharge from the nipples
- Headaches or vision changes
- Very low weight or disordered eating
- Pelvic pain or unusual bleeding
What tests might be done?
Pregnancy test, blood tests for thyroid, prolactin and other hormones, and sometimes a pelvic ultrasound.
Frequently asked questions
Can stress really stop a period?
Yes. Stress affects the brain hormones that control ovulation.
Is a late period normal sometimes?
Occasional variation of a few days is normal.
Related reading: PCOS guide · Early signs of pregnancy · Perimenopause
Checked against NHS guidance on missed periods. Updated 5 November 2026.