Fertility and Period Tracker

Fertility and Period Tracker is a scientifically based calendar that predicts your next period, ovulation day, and fertile windows. By entering the first day of your last period, your average cycle length, and luteal phase, you get data-driven insights to plan or avoid pregnancy naturally. The app synchronizes with Apple Health, so your fertility insights stay up to date across iPhone, iPad, and Apple Watch.

Two gender-prediction methods are provided: Popular (based on the Landrum Shettles theory) and Scientific (data-driven). Both offer probabilistic insights and can be switched anytime in Settings. The full version adds daily pregnancy probability, per-day gender probabilities, overall fertility chances for the current cycle, and automatic Apple Health sync. Note: this app is for educational and informational purposes and is not a substitute for professional medical advice.