I've been using this app for about 1 year or so as a natural means of birth control. When I first began using it, I wasn't having intercourse often. But for the past 4-5 months I have increased the frequency. Initially, I was using condoms as an additional method of protection, but lately I've used nothing but the app as a reference tool. Today is the first day and month I've had my period late since using the app. How accurate is the fertile timeframe? Has anyone else had similar issues? How accurate has this app been for you? I haven't had any of the normal signs that I'm pregnant, but I am concerned about being late. Please help!