AF never came..

Alyssa
AF was due on the 3rd and NEVER came. I was starting to wonder if maybe I was pregnant and was going to take a test yesterday. Well for some reason I thought since it's supposed to be around my ovulation if I would have gotten my period I should just take an ovulation test first and see what it says. And I am definitely ovulating! My question is if you missed a period how are you still ovulating at the the same time you normally would be when AF didn't show up...?