Does anyone know how accurate is this <a href="https://play.google.com/store/apps/details?id=com.glow.android">Glow app</a> I'm a bit worried since the previous app I used had my fertility days wrong and I had unprotected sex on the days i thought i was not fertile but apparently other apps including this one is saying I was fertile at the time I had unprotected sex. Point is I'm trying to avoid pregnancy and I don't want to go on birth control. How accurate is this app anyone?