Don't know what to do...

I use Ovia. It originally predicted my fertile window to be the first week of February, I got a negative hpt. Well, now it is saying it was two weeks ago. My period should have started but in theory it is two weeks late. (CD51 is what Im on now). About 2 weeks ago I took two hpt's and even had blood work done, all neg. Should I test again or just stop overthinking and creating false hope? Ugh