21 Day Cycle Overview
Ovulation: Day 7
High Fertility: Day 2 – 8 | Next Period: Day 22
Tracking a 21-Day Cycle
For a consistent 21-day cycle, your next period will begin exactly 21 days after the first day of full bleeding from your previous cycle. While apps use averages, your biology dictates that the follicular phase (the days leading up to ovulation) is what causes this specific length.
Your Specific Cycle Metrics
| Cycle Day | Biological Event |
|---|---|
| Day 1 | First day of period (Full Flow) |
| Day 2 - 8 | High Fertility Window |
| Day 7 | Estimated Ovulation |
| Day 22 | Next expected period / Testing Day |