Is My Fertility Data Private? What to Know About Cycle-Tracking Apps

Whether your fertility data is private depends entirely on the app you use. Many popular period and fertility trackers store your data on their own servers, and some have shared sensitive information with third parties or used it for advertising, which has drawn regulatory scrutiny and made privacy a genuine concern. The most protective approach is an app that keeps your data on your own device rather than in the cloud.

Why is fertility data so sensitive?

Cycle and fertility data can reveal when you are trying to conceive, whether you might be pregnant, and intimate details of your reproductive life. That makes it some of the most personal information you can record. Concern about this data has grown, and research found that some people changed or stopped using tracking technologies after the 2022 Dobbs decision in the United States (Contraception, 2025).

What do period and fertility apps do with your data?

It varies widely. Some apps store your data on their servers, use it to build advertising profiles, or share it with third parties, and several have faced investigations or regulatory action over how they handled sensitive information. Others take a privacy-first approach and keep your data on your device. The only way to know for sure is to read the app's privacy policy and check where your data is stored and who it is shared with.

How do I check if an app is private?

Look for a few things. Is your data stored on your device or in the cloud? Does the app share or sell data to third parties or advertisers? Does it require an account tied to your real identity? And is its privacy policy clear and specific? Vague policies, mandatory sign-ups, and data used for advertising are all warning signs.

What makes an app privacy-first?

A privacy-first app keeps your data on your own device, does not sell or share it with advertisers, collects as little as possible, and is transparent about all of it. If your data never leaves your phone, there is nothing sitting on a server for a company to share, a marketer to buy, or a third party to request.

How Majella helps

Majella is built privacy-first for exactly this reason. Your cycle and fertility data is kept private on your own device rather than sold or shared, so the intimate details you record stay with you. Cycle tracking is free, and NFP features are available on a paid plan.

Related reading: What Is Natural Family Planning? A Complete Guide and How to Track Your Cycle with Basal Body Temperature and Cervical Mucus.

Frequently asked questions

Do period tracking apps sell your data?

Some do, or share sensitive data with third parties and advertisers, which is why several have faced regulatory scrutiny. Others do not. Always check the app's privacy policy and where it stores your data.

Is it safer to keep fertility data on my phone?

Generally yes. If your data is stored only on your own device rather than a company's servers, there is nothing in the cloud for a company to share or a third party to request.

What should I look for in a privacy policy?

Check where your data is stored, whether it is shared or sold, whether it is used for advertising, and whether an account tied to your identity is required. Clear, specific policies are a good sign.

This article is for general information. Privacy practices differ between apps and can change, so review each app's current privacy policy for the most accurate details.

References: Use of period- or fertility-tracking technologies pre- and post-Dobbs. Contraception. 2025.