my best suggestion is to but some cheap ovulation predictor kits. the apps are not always right.

I don't know how many days like it'll say 28? I don't.know that tho. . @khaydensmommy

the app "period diary" was helpful for me, and then I also got an ovulation kit.

You can google search the Ovulation calendar it will ask you when your last menstral cycle was and it will show your Ovulation days and what days you are most fertile