Period after the pill

Due to an issue with my prescription, I had to stop taking birth control a month ago. Since then, my husband and I have used withdrawal and I've tried to pay attention to my body to check if I ovulate (which I thought I did on CD17). My period is now 7 days late according to Glow (CD37). I know that your cycle can vary greatly after stopping BC so I'm trying not to stress out about it. I've also taken two pregnancy tests on CD28 and CD33 that were both negative. Was I totally wrong about ovulating, is there still a chance of pregnancy, and how long did it take for your period to arrive?