I had a missed abortion at13 weeks got a d&c right after. its been 8 weeks and haven't got my period, only clearish light pinkish brownish light flow.

Takes a while: After a stress like that to your body, it can take a few menstrual cycles to get into a proper routine. If you don't feel like your are having a normal menstrual cycle in the next month, go to your OB and discuss in detail. I suspect your menstrual flow will improve with each successive month. You can check on ovulation mid-cycle with an ovulation kit, if you are in TTC mode