Can take 4-6 weeks i was told hun, im still waiting for Mine, but i only just got a positive opk on new years day that was 4 weeks from main bleed of miscarriage, so my af could come in 2 weeks time if no bfp!! So dont worry depends when the hcg came out of your system altho u miscarried on the 3rd, the hcg can take upto 2 weeks to leave your system, and your cycle wont start again until thats gonex