I've been using <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a> for a couple months now and it really does help me know when I'm going to get my period but last month my period came 6 days early and this month it came 10 days early. My period usually lasts a week and I've been off it for only 8 days since my last one. Idk if I should be worried :(