I've had this app for over 4 months and it has never let me down on when I'm supposed to start my period and when I'm ovulating.. sadly I've had no luck getting pregnant. 😔 usually 2-3 days before my period comes I get bad cramps and I'm supposed to start my period tomorrow but the last 2 days all I've been feeling is nauseous.. How long should I wait to take a test? or should I just wait a week and see if it's just late?