Period Tracker
Log the first day of your recent periods to get your true average cycle, how regular you are, and your next twelve dates.
Log your periods
Enter the first day of bleeding for each. Three or more gives a useful average.
Cycle-to-cycle variation
Length in days of each completed cycle.
Your next period
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Add at least two dates
Average cycle
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Range
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shortest - longest
Regularity
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Cycle day today
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Next 12 predicted periods
| # | Predicted start | Day | In |
|---|
Predictions, not contraception. Cycle timing shifts with stress, illness, travel and weight change. Never rely on a predicted date to avoid pregnancy.
See a doctor if your cycles are consistently under 21 or over 35 days, if you skip three or more, or if bleeding is unusually heavy. Heavy periods are a common cause of depleted iron stores - see hair fall and the ferritin test.
Frequently asked questions
What is a normal cycle length?
Most cycles run 21 to 35 days, measured from the first day of one period to the first day of the next. A few days' variation between cycles is entirely normal - perfectly identical cycles are the exception, not the rule.
How many periods should I log?
At least three, ideally six. One cycle tells you almost nothing, because natural variation is wide enough that any single number could be an outlier.
My period is late - does that mean I'm pregnant?
It might, but stress, illness, significant weight change, travel across time zones, heavy exercise and thyroid or hormonal conditions all delay periods. A home pregnancy test from the day of your missed period is reliable.
When should irregular periods be checked?
See a gynaecologist if cycles are consistently under 21 days or over 35, if you skip three or more in a row, if bleeding lasts more than seven days or is unusually heavy, or if you bleed between periods. PCOS and thyroid conditions are common and treatable.