Clue uses the estimates you selected during the initial setup only until you have completed your first cycle.
After your first cycle is complete, Clue creates predictions based on the data you enter. You can still update Clue's estimates by entering a cycle of past data into Clue. This data will create averages that will override the estimates you chose during Clue's setup screens.
Another option is for you to delete and reinstall Clue. Deleting Clue will delete all of your data, unless you've backed up your Android device using another program.