I was on sprintec birth control for the past 3

Patient: I was on sprintec birth control for the past 3 years continuously. About two months ago, I stopped to try to have a baby. As soon as I stopped I got my period like I normally would 28/day cycle which means I should have started again this past Wednesday. It’s not Saturday almost Sunday and I have not started. I am wiping brown/red but not like normal period. No clots nothing like that. Cramping a little as well. Took pregnancy test yesterday ..came back negative. Never been late always been on 28 day cycle..what’s going on?

Doctor: