Period

Ca

So according to <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a> I was supposed to start my period 5 days ago but I haven’t so therefore I’m late. So is <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a> really that accurate?