Fertility & Ovulation Tracker Excel — BBT Chart, Automatic Ovulation Detection & Fertile Window

Uses the same basal body temperature (BBT) coverline method fertility apps are built on, but fully

transparent and yours to keep. Log daily BBT, cervical mucus, OPK results and cycle symptoms, and the

spreadsheet automatically detects your ovulation day using a real temperature-shift formula (0.4°F+

sustained rise), calculates your fertile window, and works out your luteal phase length — flagging it

if it's on the shorter side, since a consistently short luteal phase is worth discussing with a doctor.

Includes a multi-cycle history log to track regularity and variability over time. No subscription, no

account, no ads — just the same method, in a spreadsheet you fully control.