Period Tool

Period Tracker

Track your menstrual cycle, predict your next period date, ovulation window, and fertile days — all in one simple, private tool.

100% Private Instant Results Medically Reviewed
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Track Your Period

Next Period Starts
Period Ends
Next Ovulation
Fertile Window Starts

Predictions may shift ±3–5 days due to stress or hormonal changes.

Why Tracking Your Period Matters

Your menstrual cycle is often called a "fifth vital sign" — a window into your overall hormonal and reproductive health. Regular cycles indicate healthy hormonal function. Changes in cycle length, flow, or symptoms can be early indicators of health issues including thyroid disorders, PCOS, or perimenopause.

Period tracking also helps you anticipate and prepare for menstruation, understand your fertile window, manage PMS proactively, and provide accurate cycle history to your healthcare provider.

What Is a Normal Menstrual Cycle?

A normal cycle ranges from 21–35 days, with 28 days being the average. Flow lasts 3–7 days with normal blood loss of 30–80 mL (about 2–6 tablespoons). Cycles outside the 21–35 day range consistently may warrant medical evaluation.

What Can Affect Your Cycle?

  • Stress: Cortisol disrupts GnRH pulsatility, delaying ovulation
  • Weight changes: Affects estrogen production and ovulatory function
  • Illness or travel: Temporary disruptions to hormonal rhythm
  • PCOS: Most common cause of irregular periods in reproductive-age women
  • Thyroid disorders: Both under and overactive thyroid affect cycle regularity
  • Perimenopause: Cycle changes begin 8–10 years before menopause

When Is a Period Considered Late?

A period is considered late if it hasn't arrived within 5 days of its expected date. More than 7 days late is a missed period — take a pregnancy test and consult your doctor if needed. Missing 3+ consecutive periods (secondary amenorrhea) requires prompt medical evaluation.

How many days late before I should worry?
A period 1–5 days late is usually normal variation. More than 7 days late: take a pregnancy test. More than 2 weeks late with a negative test: see your OB-GYN. Missing 3+ consecutive periods requires immediate medical evaluation.
Can I track my period without an app?
Absolutely. Use our free Period Tracker calculator above. Simply note the start date of each period in a calendar or journal, count the days between them, and use our calculator to predict the next one. No app or account required.

Medical Disclaimer: This tool is for educational purposes only and should not replace professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider for personalized guidance.

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