Note: the only wearable devices that are compatible with Natural Cycles are the Oura Ring and the Apple Watch. Learn more here.
If you’re an existing NC° user
As an existing NC° user, the Natural Cycles app will only import data from your device starting from the date you switched devices in the NC° app (even if you didn’t log any recent temperature data before switching).
The Natural Cycles app will not mix or replace temperature data from different devices (such as a thermometer and the Oura Ring/Apple Watch).
If you’re a new NC° user
As a new user who just signed up to use Natural Cycles with your Oura Ring or Apple Watch, the NC° app will use your past temperature data from the earliest period you’ve logged in your Natural Cycles app, or from the date you quit hormonal birth control if you’re starting Natural Cycles after quitting hormonal birth control. If you recently were pregnant, the data will sync from the date the pregnancy ended. The Natural Cycles app doesn’t receive any period data from your Oura App or Apple Health app (unless you’ve selected the option to import your period data from Apple Health).
You have the opportunity to inform the app of your period dates or the date you quit hormonal birth control in the setup questions. If you need to re-answer the setup questions, you can learn how to do this here.