Best Period Tracker Apps for Fertility Tracking in 2026

Fertility Tracking and Contraception: Two Different Needs

Every app in this list calls itself a “fertility tracker,” but not all fertility tracking is the same.

Calendar and prediction-based tracking uses historical cycle data to estimate likely fertile windows. Every period tracker does this. The accuracy depends on cycle regularity and the size of the algorithm’s training dataset.

Temperature-based tracking uses daily basal body temperature to detect the post-ovulation temperature rise, allowing retrospective confirmation of ovulation timing. More accurate than calendar prediction, but requires consistent daily measurement.

FDA-cleared contraception is a separate category. Only Natural Cycles holds FDA De Novo clearance as a contraceptive device. This means the FDA reviewed clinical data on effectiveness and found it sufficient. No other app on this list has this clearance.

If fertility tracking is for cycle awareness, most apps work. If fertility tracking is for contraception, Natural Cycles is the only regulated option.

The Data Risk Specific to Fertility Tracking

Fertility data is more sensitive than general cycle data. Ovulation logs, conception attempts, and pregnancy tracking create a record of intent, which matters legally in states where abortion is criminalized.

Glow’s model of sharing health data with insurers is a specific risk for fertility trackers. If an insurer learns you are trying to conceive or tracking a pregnancy, that information can affect coverage decisions. Consumer health apps are not HIPAA-covered entities, so no federal law prevents this.

Server-based apps create a subpoenable record. In states with abortion restrictions, fertility tracking data showing a missed period, a positive pregnancy test entry, or ovulation tracking around the time of a pregnancy has been sought as evidence in investigations.

On-device apps store nothing on company servers. The company cannot produce what it does not hold.

Temperature Tracking: What It Requires in Practice

Natural Cycles and Floriva both support BBT tracking, but with different requirements.

Natural Cycles makes BBT mandatory. You need a compatible thermometer accurate to two decimal places, and you measure before getting out of bed every morning. Missing multiple days reduces accuracy. The algorithm flags your cycle status based on that data, and the app requires consistent participation to function as intended.

Floriva treats BBT as an optional input. Log it if you want temperature-based cycle awareness; skip it if you want simpler tracking. Floriva’s predictions are less rigorous than Natural Cycles’ validated algorithm, but the app works for people who can’t commit to daily measurement.

Cost and Value by Use Case

For FDA-cleared contraception, Natural Cycles at $12.99/mo is the only regulated option. The cost reflects real clinical and regulatory overhead.

For fertility tracking with privacy, Floriva at $2.99/mo covers temperature tracking, ovulation prediction, and on-device storage below the price of any server-based competitor with comparable features.

For free fertility tracking with privacy, Euki covers basic ovulation and cycle logging at no cost, on-device, with a nonprofit structure that removes commercial incentive to monetize data.

Premom and Glow both have documented data-sharing practices that create specific risks for fertility trackers. Premom’s FTC enforcement (2023) covered health data shared with Chinese third parties. Glow shares health data with insurers. Both risks are concrete and documented, and on-device alternatives exist.