What's going on?!?

Kasey
My period is 13 days late according to the app and the 2 tests I took (7 days and 12 days late) came back negative. My period is pretty regular, a day or two off at most. 
A few days ago I had some really bad cramps but they weren't a constant pain. It would be pretty intense for a few minutes then dull back down. 
I have no idea what's going on with my body and it driving me crazy 😔 please any help/insight would be greatly appreciated