Ovia vs. Glow

Roni

So on my <a href="https://play.google.com/store/apps/details?id=com.glow.android">glow app</a> it says my fertile window stopped on Sunday. But, on my Ovia app it says my fertile window started on Sunday. I’m so confused on which one to go off of. Anyone else use more than one fertility tracking app and have this problem?