Set up "menstrual tracking"
1. Open the Health application on the iPhone.
2. Click Browse in the lower right corner to display the Health Category screen.
3. Click on "menstrual tracking".
4. Tap Start, and then follow the onscreen instructions to set notifications and other options.
5. Tap options, and then open the desired options: menstrual prediction, pregnancy prediction and heart rate data.
Note: If you open the menstrual prediction and pregnancy prediction in the health App on iPhone, you will receive a notice about the next menstrual period and pregnancy window on AppleWatch.