2-3 Days late

AF was due either Saturday or Sunday (depending on what app I look at). I tested on Friday with a dollar store test and a digital test and both were negative. I have cramps, diarrhea, and my breasts are tender. I think the cramps might be from the diarrhea. I don’t believe my ovulation was correct according to the app. I think it either didn’t happen or it was later. When should I test again?