Fertility Module

Plan Your Pregnancy

Ovulation tracking, fertility windows, cycle analysis, and conception tools - everything you need when trying to conceive.

Ovulation calculatorFertility windowCycle tracking
8Chart Types
7Fertility Colors
32Languages
241Countries & Territories

Ovulation & Fertility Tracking

Know your most fertile days

Ovulation Calculator

Predict your ovulation day based on cycle length. See your 5-6 day fertile window.

Fertility Window Tracker

Daily fertility status - low, high, or peak. Know the best days to try.

Cycle Length Calculator

Track your cycles over time. Calculate averages and identify irregularities.

Conception Planning

Tools to help you conceive

Conception Date Calculator

Estimate when conception occurred based on your due date or last period.

Implantation Calculator

Track the timeline from ovulation to implantation to when you can test.

Due Date Calculator

Calculate your estimated due date based on conception or last period.

Fun Predictors

For entertainment only

Chinese Gender Predictor

Ancient Chinese method using lunar age and conception month.

Mayan Gender Predictor

Mayan calculation based on age and year of conception.

Zodiac Sign Planner

Plan conception timing for your preferred zodiac sign.

Sibling Age Gap Calculator

Calculate the age gap between siblings based on due date.

Fertility Planning FAQ

Common questions about fertility tracking

Predictions improve with more cycle data. After 3+ logged cycles, the app refines your fertile-window estimate from your personal cycle history rather than population averages.

Yes! The app adapts to irregular cycles and uses multiple data points including OPK results and symptoms to improve predictions.

No, OPK logging is optional. The app calculates fertility windows from cycle data alone. OPK data improves accuracy when available.

Yes. All data is stored locally on your device first. Cloud sync is optional and encrypted. Intercourse data is never shared with family members.

Your cycle data seamlessly transitions to pregnancy mode. Conception date is auto-calculated and due date is predicted from your cycle data.

Start Your Fertility Journey

Download ProbaBaby for free fertility tracking tools.

Download on the App Store
  • Free to download
  • No subscription
  • 30+ free tools