There is no official day count for a “missed” period, so this calculator counts two things from your own cycle length: how many expected period dates have been reached with no period, and how many full cycles have passed since the first of them. The first question is always the same: could this be pregnancy? Enter two numbers below to see where you are and what to do at your stage.
Expected dates reached with no period, and full cycles passed after the first one. A few days past the date is “late”.
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.
Three different things get called a “missed period” — and each one has a different next step:
A few days past the date is ordinary variation; the late period calculator reads the day count.
This page counts the expected dates reached and, separately, the full cycles that pass after the first one.
Its own category with its own causes — including, when pregnancy is possible, implantation bleeding.
More than one full cycle with no period? Then the question is no longer timing but cause — the table below and, at the thresholds further down, a clinician.
There is no official day count where “late” becomes “missed”, so the calculator uses your own cycle length as the ruler and reports two numbers that differ by one. Example: last period August 1, 28-day cycle, today October 27 — 87 days since the last period began. Expected dates August 29, September 26 and October 24 have all been reached — 3 expected dates; from the first of them to the last, 2 full cycles have passed. The expected date itself counts as reached, so on that day the result reads “expected date reached — 0 days past it”, not late:
| Stage | Days since the last period began (28-day cycle) | What it usually means | Next step |
|---|---|---|---|
| Expected date not reached yet | 0–27 | Not due yet | Very sensitive tests can work a few days early; most tests from the expected date — see pregnancy test timing |
| Expected date reached, up to 6 days past it | 28–34 | Usual variation | If pregnancy is possible, test (most tests work from the first day of a missed period, NHS); day-by-day scale on the late period calculator |
| 7+ days past the first expected date | 35–55 | Beyond the usual variation; no full extra cycle yet | Pregnancy test if sexually active |
| 2 expected dates reached · 1 full cycle past the first | 56–83 | A whole cycle with no period | Test (or retest); start noting possible causes |
| 3 expected dates reached · 2 full cycles past the first, under 90 days | 84–89 | Two cycles with no period | Test; book a clinician visit |
| 90+ days, no period | 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 | Around the expected period — most about 10–14 days after ovulation (Cleveland Clinic) | 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:
Home tests detect hCG, which only starts after implantation and needs days to rise. A negative before the test can see it proves little.
The luteal phase runs 10–15 days in real-world data (600,000+ cycles), and everything after ovulation shifts with it — a “missed” period can turn out to be a very late one.
The protocol:
If a test turns positive, the next section walks through what to do. For testing timing in detail, the pregnancy test calculator covers it — and if you track ovulation rather than period dates, your expected period ≈ ovulation + 14 days, which its ovulation-day mode computes directly.
A positive home test is almost certainly correct (NHS). The next few weeks are more routine than the internet makes them feel — four things, in order:
And if this pregnancy was not planned: you do not have to decide anything today. A healthcare provider or an options counseling service can walk through every path — without judgment — whenever you are ready.
From most to least urgent — and you can always ask sooner:
Urgent care — possible ectopic pregnancy, even if the test is negative. No test result rules an ectopic out (NHS).
Book a visit even before the 90-day line.
The definition of secondary amenorrhea — see a clinician (negative test assumed).
Where the definition sits for previously irregular cycles (Cleveland Clinic). You don’t have to wait that long to ask.
ACOG’s thresholds for evaluating a first period that hasn’t come.
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.
Where to go from here:
There is no single official day count. This calculator shows two things: how many expected period dates have been reached with no period, and how many full cycles have passed after the first one. 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). If you still think you could be pregnant, test again in a few days; if a second test is negative and your period still hasn’t come, see a GP (NHS). Had unprotected sex since the test? Test at least 21 days after the most recent time (NHS).
No. An ectopic — a pregnancy implanted outside the womb — can show a positive or a negative test, so no result rules it out. What settles it is symptoms and a scan: a missed period with severe one-sided pelvic pain, dizziness or fainting, shoulder-tip pain, or unusual persistent spotting needs urgent care, even with a negative test (NHS).
No official line exists. On a 28-day cycle the expected date is reached 28 days after your last period began; one full cycle after it is 56 days, two are 84 days. At 87 days, for example, three expected dates have been reached and two full cycles have passed after the first — the calculator shows both numbers.
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.
Approximately, yes: conception happens within about a day of ovulation, and ovulation ≈ cycle length − 14 days after your last period started — around day 14 on a 28-day cycle. The conception calculator back-calculates from the dates you know. Two honest limits: real luteal phases vary 10–15 days, so the estimate can sit several days either side; and with irregular cycles, an “ovulation day” from an app is itself a guess.
Count from the first day of your last period, not from the positive test or the day you conceived. If your last period started 6 weeks ago, you are 6 weeks pregnant — conception happened about 4 weeks ago (roughly 2 weeks after that period started, on a typical cycle). The due date calculator does the math and estimates your due date (last period + 280 days).
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.