Should I have already started my period? I've been taking Norethindrone tablets USP, 0.35 mg since June 1, 2015 and I have not had my period yet. I was still vaginally bleeding from my c-section (May 19) when I started taking it and haven't bled or spotted since. I've taken numerous pregnancy tests and they have all came back negative. I exclusively pump my breast milk and formula feed, I do not latch my baby if that matters. So, should I have started my period?