Free Menstrual Cycle Tracker

Track your menstrual cycle length and predict your next period, ovulation, and PMS window.

days
days
days

Days Until Next Period

13 days

Current Cycle Day15
Ovulation Expected on Day14
PMS Window Starts Day21

Days Until Next Period vs Period Duration

Menstrual Cycle Phases

Typical 28-Day Cycle

PhaseDaysDescription Menstruation1-5Period bleeding Follicular1-13Follicle development Ovulation~14Egg release Luteal15-28Post-ovulation PMS Window~21-28Premenstrual symptoms

Next Period = Cycle Length - Days Since Last Period Ovulation Day = Cycle Length - 14

Example Calculation

A 28-day cycle, period lasts 5 days, currently on day 15.

  1. 01Next period in = 28 - 15 = 13 days
  2. 02Ovulation day = 28 - 14 = Day 14 (just passed)
  3. 03PMS window starts = Day 21 (in 6 days)

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