All 3 period trackers tell me something diff

Kim

So. I’m crazy and have 3 different period/fertile apps. All 3 of them say I’m supposed to start/ end periods differently which means my ovulation and fertility dates are different. They all have the exact same info. I don’t do anything different with any of them. So I just never know. I guess I’m kinda winging it. And yes, we do that baby dance for all 3 apps just in case. April is when I can go back to the OB to talk about infertility ( 6 Month due to the fact I’m 35) I guess which one is right? Or anyone have any suggestions or comments. Anything.