<a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a> has been expecting my period to come earlier every month and it's been right. When I started using the app, my period started around the 20th of every month. It's been a few months now and this time my period started the 9th. By September, <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">eve</a> has it predicted to start the 4th?? Does anyone know why??