App problems?

App was fine until my period days. Almost a year ago I stopped using the birth control patch after being on it for a few years. My period did not come for months and still was not regular. So when it came time for my period when I started using this app my period did not happen . Since then the app always says I have logged my days when I have not. Also says I check my CM and I check no on that. Anyone else have problems. What am I doing wrong????