6 weeks after my miscarriage and still haven't had a period why?

Hormones: I tell women it can take 6 to 8 weeks to have a cycle that's normal following a miscarriage. Sometimes the lining has to build all the way back up again, in order to have something to bleed from. At this point i wouldn't worry. Likely time will give you your answer. If after another 2 to 3 weeks you still haven't had a cycle consider consulting your gynecologist.