Know where you are in your cycle.
Enter your last period once. Every visit after that opens on today: your cycle day, the next expected period, and the estimated fertile window.
Painful periods? What actually helps, honestly.
Common questions
How accurate is a period calculator?
For regular cycles, usually within a few days: the calendar method simply projects your own average forward. Accuracy drops with irregular cycles, stress, travel, illness, breastfeeding and the years around perimenopause. Track two or three cycles and the estimate tightens because it is built on your real numbers.
When is my fertile window?
Ovulation lands about 14 days before the NEXT period starts, not 14 days after the last one, which is why cycle length matters. Sperm survive up to five days, so the fertile window runs from roughly five days before ovulation to a day after. Calendar estimates are useful for planning and awareness, but they are far too imprecise to rely on as contraception.
What counts as an irregular period?
Cycles shorter than 21 days, longer than 35, or swinging widely from month to month. Occasional irregularity is normal, especially in the teens and in the years before menopause. Persistent irregularity is worth a doctor visit because thyroid problems and PCOS are common, checkable causes.
When should I see a doctor about my period?
Soaking through a pad or tampon every hour, bleeding longer than 7 days, bleeding between periods or after sex, pain that regular painkillers do not touch, or a previously regular cycle that stops for three months. None of these are for toughing out; all of them are conversations a doctor can actually do something about.
How many days between periods is normal?
Anywhere from 21 to 35 days counts as regular for adults, and your own rhythm matters more than the textbook 28. Cycles that suddenly change pattern, arrive closer than 21 days, spread past 35, or go missing deserve a doctor conversation, and a few months of tracked dates is exactly the evidence that makes that visit quick.