The iPhone Health app’s Cycle Tracking feature provides a simple solution for logging menstrual cycles. If you menstruate, it’s an effective way to monitor your overall health and estimate when you’re most likely to get pregnant.

Given the personal nature of Cycle Tracking data, you need to be sure that it’s stored securely, away from prying eyes. The good news is, Apple’s security for health and fitness data is very robust. There are just a few things you need to know to ensure your data is safe.