Read Your Body never marks the start of a new menstrual cycle for you!
When you enter a day of bleeding in the app that comes after a day without bleeding, you'll see a dialog asking you if it's the start of a new menstrual cycle today - you can answer yes or no, and the start of a new menstrual cycle will be marked in the app if you answer yes.
If you ever need to add or remove the start of a menstrual cycle in the app outside of this situation, you can do so via the app's chart or data screen - see below.
Chart screen
Single tap any day of bleeding in the fluid / stamps row on your chart screen, then tap the 'Start of new cycle' icon 🔄 to add / remove the cycle start as needed:
Data screen
Scroll in your calendar screen to find the day that you want to edit, tap it once then tap the 'Edit' option in the dialog to be taken to your data screen for that day.
In the fluid / stamps section of your data screen, toggle on / off the 'Start of new cycle' option to add / remove the cycle start as needed:
💡 Mark the start of a new menstrual cycle in the app whenever you experience the start of menstruation or the end of pregnancy / day of childbirth.
🩸 The start of menstruation is the first day of fresh bleeding (i.e. not including premenstrual spotting) typically 10-16 days after confirmed ovulation - even if the fresh bleeding starts in the evening that would be considered the start of a new menstrual cycle today.