How is a late period calculated?
Your expected period date is found by adding your own cycle length to the first day of your last period. In a 28-day cycle, if your period started on March 1, your next period is expected around March 29. If today is after the expected date, the number of days in between is how late your period is.
If your cycle is irregular, the estimate may be off. If you know your shortest and longest cycles, entering the longer one helps you avoid unnecessary worry. Logging your cycle for a few months makes your average clearer.
What to do if your period is late
- 1-3 days: This is usually a normal fluctuation. If you could be pregnant, you can take a home test during this time.
- One week: If your test is negative, repeat it with morning urine or get a blood test (beta hCG).
- Three months or more: If you are not pregnant, see your doctor so the cause can be looked into.
If your test is positive, you can track your pregnancy in the HeyMom app; if not, the ovulation calculator helps you plan your next cycle.
Frequently asked questions
How late can a period be and still be normal?
Cycle length can change by a few days from month to month. Cycles of 21-35 days are considered normal, and a period that comes 5-7 days after the expected day is often not a sign of a problem. Stress, lack of sleep, illness, intense exercise and weight changes can delay your period.
When should I take a pregnancy test if my period is late?
Home urine tests give the most reliable result from the first day your period is late onward. If the result is negative and your period still has not come, repeat the test 3-7 days later with your first morning urine. A blood test (beta hCG) gives an earlier and more accurate result.
My test is negative but my period has not come. What should I do?
A single negative test does not rule out pregnancy for certain, especially if you tested early. Repeat the test a week later. If you are not pregnant and your period has not come for 3 months, or if you have severe pain or abnormal bleeding, see an OB-GYN.
What causes a late period other than pregnancy?
The most common causes are stress, sudden weight loss or gain, intense exercise, breastfeeding, thyroid problems, polycystic ovary syndrome (PCOS), some medications and the transition to menopause. If the irregularity keeps coming back, your doctor will look for the cause.
