A missed period means a full expected cycle has passed with no bleeding — not just a few days late. And the first question to answer is always the same: could this be pregnancy? Enter two numbers below to see how many cycles you may have skipped and what to do at your stage.
A full expected cycle passes with no bleeding. A few days late is "late," not missed.
If pregnancy is possible, test first. Most home tests work from the first day of a missed period.
No period for 90+ days is secondary amenorrhea — that threshold means see a clinician.
A missed period is not a late period, and it is not light spotting. "Late" means the bleeding eventually arrives, past the expected date. "Missed" means one full cycle's expected bleeding never happened. And spotting — a few drops that never become a flow — is a third category with its own causes (see the comparison below).
The distinction matters because the next step is different at each stage. A few days late usually means do nothing. A missed period means rule out pregnancy. Repeatedly missed periods mean look for the underlying cause with a clinician.
There is no official day-count where "late" becomes "missed," so use your own cycle length as the ruler. Each time an expected period date passes with no bleeding, that is one missed period:
| Stage | Example on a 28-day cycle | What it usually means | Next step |
|---|---|---|---|
| Expected date not reached yet | Before day 28 | Not late, not missed | Wait — see the late period calculator for the days scale |
| 1–6 days past expected | Day 29–34 | Normal variation | Wait — day-by-day scale on the late period calculator |
| 7+ days past expected, first cycle | Day 35–55 | A real late period | Pregnancy test if sexually active |
| One full cycle skipped | Day 56–83 | One missed period | Test (or retest); start noting possible causes |
| Two cycles skipped, under 90 days | Day 84–89 | Repeated missed periods | Test; book a clinician visit |
| 90+ days, no period | Day 90+ | Secondary amenorrhea (clinical threshold) | See a clinician |
Pregnancy is the most common cause of a missed period in the reproductive years — which is why testing always comes first. Beyond pregnancy, every other cause works through the same mechanism: something suppresses or disrupts ovulation, and no ovulation means no period.
| Cause | How it pauses periods | Typical clue |
|---|---|---|
| Breastfeeding | Prolactin suppresses ovulation | Expected — cycles return when nursing slows |
| Perimenopause | Ovarian hormone output becomes erratic | Typically 40s; cycles lengthen or shorten unpredictably |
| Stress, low weight, intense exercise | Brain dials down the ovulation signal (functional hypothalamic pattern) | Coincides with a stressful period, weight change, or training block |
| PCOS | Ovulation happens rarely or not at all | Long-standing irregularity, often since the teens |
| Thyroid conditions | Thyroid hormones feed into the cycle-regulating axis | Fatigue, temperature sensitivity, unexplained weight change |
| Hormonal birth control & stopping it | The medication schedule replaces your own cycle | Withdrawal bleeding pattern on it; a few months to restart after stopping |
| Emergency contraception (morning-after pill) | A high hormone dose deliberately delays ovulation | Next period can be up to a week late; test if no period within 3 weeks of taking it (Mayo Clinic) |
Late means the period arrives after the expected date; missed means a whole cycle's bleeding never came. If you are only days past your expected date, the late period calculator is the right tool — this page is for when a full cycle has gone by.
Light spotting around the time a period is due can be implantation bleeding — an early-pregnancy sign that is easy to mistake for a very light period:
| Implantation bleeding | Normal period | Withdrawal bleeding (on hormonal BC) | |
|---|---|---|---|
| Timing | 6–12 days after ovulation — often just before the expected period | On your cycle schedule | On the pill-free / patch-free week |
| Flow | Spotting — a few drops, no flow | Full flow needing pads/tampons | Usually lighter than a natural period |
| Duration | A few hours to 2–3 days at most | Up to 8 days (FIGO normal range) | A few days |
A negative test with no period has two main explanations. First, the test may have been taken too early: home tests detect hCG, and hCG needs time to rise after implantation. Second — and more often — ovulation simply happened much later than usual this cycle, so your period is not actually due yet. Real-world data on 600,000+ cycles shows the luteal phase runs 10–15 days rather than the textbook 14, which is exactly how a "missed" period can turn out to be a very late one.
The protocol: retest in a week. Still negative and still nothing? The cause is likely not pregnancy, and the causes table above becomes the relevant reading. At 90 days total, stop testing and see a clinician.
If a test turns positive, the due date calculator estimates your due date from your last period, and the pregnancy test calculator explains testing timing in detail.
The counting is exact: days since your last period and cycles elapsed are simple arithmetic. What no calculator can do is tell you why a period is missing — that takes a pregnancy test, and past the thresholds above, a clinician. Use this tool as a router, not a diagnosis. The formulas and sources are on the methodology page.
If it turns out you are late rather than missed, the late period calculator reads the day count for you. For ongoing irregular cycles, the irregular period calculator predicts a range instead of a single day, and the main period calculator covers next period, ovulation, and fertile window in one view.
A full expected cycle passes with no bleeding — not just a few days late. Clinically, no period for 90 days or more is secondary amenorrhea.
Pregnancy is the most common cause in the reproductive years, but not the only one — breastfeeding, perimenopause, stress, rapid weight change, intense exercise, PCOS, thyroid conditions, and medications can all pause ovulation. See the causes table above.
Either the test was too early, or ovulation happened much later than usual (the luteal phase runs 10–15 days, not a fixed 14). Retest in a week; at 90 days total, see a clinician.
No official line exists. A practical ruler: once one full cycle length has passed beyond your expected date — day 56 on a 28-day cycle — you have missed one period.
Yes. Significant stress can suppress the brain signal that triggers ovulation — no ovulation, no period. Cycles typically restart once the stressor resolves.
Test first if pregnancy is possible. If negative, book a clinician visit — two missed cycles is close enough to the 90-day threshold that waiting longer rarely adds information.
90+ days with no period; two or more newly skipped cycles; a teen with no first period by age 15 or within 3 years of breast development; or any missed period with severe pain, dizziness, or unusual bleeding.
In the first years after menarche, yes — ACOG considers 21–45 day cycles normal while the hormone axis matures. But the 90-day rule applies at any age.
Yes, and it is expected in both cases: breastfeeding suppresses ovulation, and hormonal birth control replaces your cycle with scheduled withdrawal bleeding. After stopping, natural cycles can take a few months to return. If your own cycle has not returned within 90 days of stopping, that crosses the secondary amenorrhea threshold — see a clinician rather than waiting longer.
Yes. It works by delaying ovulation, so it can push your next period back — Mayo Clinic says by up to one week, and the next bleed may be lighter or heavier than usual. If you have no period within 3 weeks of taking it, take a pregnancy test. Beyond that, the usual missed-period thresholds apply.
If pregnancy is genuinely impossible, skip the test — the staging table above still applies to you. One skipped cycle usually resolves on its own; two or more newly skipped cycles is a good point to book a clinician visit, and 90 days with no period is secondary amenorrhea, which always warrants one.
Possibly either, so test first — pregnancy is still possible during perimenopause. A change in period pattern (cycles lengthening, shortening, or being skipped) is usually one of the first signs of perimenopause (NHS), and menopause is only confirmed after 12 months with no period. Until then, the same test-first rule applies as at any other age.
There is no fixed maximum — the useful ruler is your own longest recorded cycle. Within your normal range, a late period is variation. Past it, test if there is any chance of pregnancy; at 90 days with no period, see a clinician regardless.
The day and cycle counting is exact; the interpretation is a routing guide. Only a pregnancy test — and past the thresholds above, a clinician — can tell you why a period is missing.