Period Calculator
Women's Health by checkit.health
How period prediction works
Your next period is estimated by adding your cycle length to the first day of your last period. A “cycle” runs from day 1 of one period to day 1 of the next — most commonly 28 days, but anywhere from 21 to 35 days is typical.
Why predictions can be off
Cycles naturally vary month to month, and stress, illness, travel, exercise and some medicines can shift things. Tracking your cycle for a few months gives a more reliable average to use here.
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Educational use only. checkit.health calculators provide general information and are not a medical diagnosis or a substitute for professional advice. Always talk to a qualified healthcare professional about your health, symptoms or before making changes to medication, diet or exercise.
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