Help with understanding ovulation

Sorry to post this on her but I am just a little confused. According to the <a href="https://play.google.com/store/apps/details?id=com.glow.android">Glow app</a> I should have ovulated about two weeks ago and I am due to get my period later this week. Just for fun I decided to take the ovulation

test and to me it looks like it’s positive. Can anyone give any insight? Is this common that the app doesn’t necessarily sync up with what is happening to you