As far as my period and fertile window the app was correct but off by a few days I would of missed my peak. I started taking my opks the second day of my last period. Which originally I was going to Wait. Then I kept testing but today I was going to take a day off but then I woke up and tested and got a positive opk. So tomorrow I should ovulate but I’m still going to bd today . But I keep seeing women who solely go by the app and don’t realize how it’d not fully accurate. But it becomes more accurate as you use it. L