It took me 8 weeks to get my period after I naturally miscarried at 12 weeks, though the abdominal sac was only dated 6 weeks 2 days.
So in all I miscarried in May and got my period in July --exactly 8 weeks 2 days. I'm having my period right now and its very very heavy. I hope you don't have the same expericne as me!
mine came back just like it should of only 2 days late