You can edit the estimates you selected during Clue's setup screens in the "Profile" section.
- Tap on "More" in the bottom navigation.
- Tap on your profile, on top of the page.
- Tap on "Averages."
After your first cycle is complete, Clue creates predictions based on the data you enter and this option will no longer be available. Clue then determines your cycle length by averaging your past cycles and it gets more precise over time.