Why “day 14” is a myth

The idea that everyone ovulates on day 14 comes from averaging a textbook 28-day cycle. Real cycles vary, and the first half (the follicular phase) is the part that stretches and shrinks.

Pinning fertility to day 14 can put the predicted fertile window in the wrong place entirely. That's why this app never hard-codes it.

Instead, we estimate ovulation from your actual signals and your own history, and we always show a window with a confidence band — never a single certain day.