Almost there

This app needs your own free Firebase project so your data stays private to you and your partner. One-time setup:

Go to console.firebase.google.com → create a project (free).
Build → Realtime Database → Create database → start in locked mode.
In the database Rules tab, paste the rules from the README and Publish.
Project settings → Your apps → Web app → copy the firebaseConfig values.
Paste them into the FIREBASE_CONFIG block near the top of this file's <script>, then re-deploy.

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Avg cycle

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Next period

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Next ovulation

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MonTueWedThuFriSatSun

Period Predicted Fertile window Ovulation Today

Your body, phase by phase

Trying to conceive? The best window is the 2–3 days before ovulation plus ovulation day. Having sex every 1–2 days through the fertile window gives the best odds. A positive LH (ovulation) test usually shows ~24–36h before ovulation — log it on the day and the app locks that cycle's prediction.

These predictions are estimates based on your logged dates and standard cycle biology — not medical advice. Calendar timing can't confirm ovulation on its own; LH tests make it sharper. If cycles are very irregular, or you've been trying 12 months (or 6 if over 35) without success, it's worth speaking with a doctor.

Settings & sync

Tune the prediction and connect Google Calendar.

Average cycle (days)

Luteal length

Ovulation → period. Default 14.

Google Calendar feed

Subscribe once — it auto-updates fertile & ovulation dates as you log periods (Google refreshes every several hours).

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In Google Calendar (web): Other calendars → + → From URL, paste, Add.

This private link

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Open this on any device to see the same data. Treat it like a password — anyone with the link can view it.

Almost there

Cycle

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Settings & sync