Taken a pregnancy test and it's negative — but still no period? Here are the most common reasons your cycle is running late.
A late period is one of the most common reasons women seek health information — and pregnancy is just one of many explanations. Your period is considered late when it hasn't arrived within 5 days of your expected date. It's considered "missed" if you're more than 6 weeks since your last period.
If there's any chance you could be pregnant, take a test first. Modern home pregnancy tests are accurate from the first day of a missed period. A clear negative result at that point is reliable. If you're sure you're not pregnant, read on.
The most common non-pregnancy cause. High cortisol signals the hypothalamus to suppress GnRH — the hormone that starts the ovulation cascade. Without timely ovulation, your period arrives late. Both acute stress (an exam, a bereavement) and chronic stress can cause delays of days to weeks.
PCOS is the most common hormonal condition in women of reproductive age and the leading cause of irregular or infrequent periods. Elevated androgens and insulin resistance disrupt ovulation, causing cycles to be unpredictable, skipped entirely, or delayed by weeks.
Both hypothyroidism (underactive) and hyperthyroidism (overactive) disrupt the hormonal axis that controls menstruation. Hypothyroidism is more common and often causes heavier, less frequent, or delayed periods. A simple blood test (TSH) can diagnose thyroid issues.
Both significant weight gain and rapid weight loss can disrupt ovulation and delay periods. Fat cells produce estrogen — too little or too much body fat alters estrogen balance and can suppress ovulation.
High training volume combined with insufficient calorie intake causes "functional hypothalamic amenorrhoea" — the brain essentially shuts down reproductive function to conserve energy. Common in athletes, dancers, and women who have dramatically increased exercise without eating more.
Starting the pill, IUD, implant, or injection can temporarily alter cycle timing. Stopping hormonal contraception can cause "post-pill amenorrhoea" — periods that take a few months to return as your body's natural hormone production resumes.
If you're in your 40s (or sometimes late 30s), irregular, late, or skipped periods can be an early sign of perimenopause — the transition towards menopause. Fluctuating estrogen causes unpredictable ovulation and cycle timing.
A significant illness (flu, COVID-19, infection) or major travel — especially crossing time zones — can shift ovulation timing and delay your period. This usually self-corrects by the following cycle.
Prolactin — the hormone that triggers milk production — suppresses ovulation. Outside of breastfeeding, elevated prolactin can be caused by a benign pituitary tumour (prolactinoma), certain medications, or hypothyroidism. It often causes irregular or absent periods.
Antipsychotics, antidepressants, chemotherapy, blood pressure medications, and steroids can all affect menstrual regularity. If a late period coincides with a new or changed medication, discuss it with your prescribing doctor.
Cycles aren't clockwork. Even women with regular cycles have variation of ±7 days month to month. If your cycle is normally 28 days but ran 33 days this month with no other explanation, it's likely just natural variation.
Premature ovarian insufficiency (POI), Asherman's syndrome (uterine scarring), or other structural conditions can cause delayed or absent periods. These are less common but worth investigating if periods are consistently absent or irregular without another explanation.
Log period dates, symptoms, and cycle patterns with WomensPal. See your history at a glance and know when something's changed.
Start tracking free →A period 1–7 days late is within normal cycle variation. Periods are officially "late" after 5 days past the expected date, and "missed" if more than 6 weeks have passed since the last period.
Yes. High cortisol suppresses GnRH, which is needed to trigger ovulation. Without timely ovulation, the luteal phase begins later, pushing back the period. Both acute and chronic stress can cause delays.
Take a test on the first day of your missed period or at least 21 days after unprotected sex. A negative result on the day of a missed period is usually reliable with a modern sensitive test.
Yes. Intense or sudden increases in exercise — especially combined with low calorie intake — can suppress ovulation through functional hypothalamic amenorrhoea. Elite athletes and women who have dramatically increased training volume are most at risk.
Related: Can Stress Delay Your Period? · Irregular Periods · PCOS Symptoms · Period Calculator