4-6 weeks normal, and anything up to 3 months after an ERPC before they do anything. I've normally been a week late, but everyone is different. Your cycle has to reset itself once the HCG is negative. If you've had unprotected sex this cycle you might want to take a test, but don't get your hopes up too much, it's normal to be 'late'
I had an ERPC on 18th November. I bled everyday for 4 1/2 weeks and then last week I got my AF - although I think it was what they call an altered AF. I did go to hospital because of the continual bleeding and they did see that I had ovulated and AF was on her way. I had a heavy period but only for 3 days. Everyone really is different. As above, I was told originally 4-6 weeks after ERPC but it depends on how far along you were, and therefore how high your HCG levels were etc. I had a mmc, baby died at 10 1/2 weeks and my pregnancy test was still positive 4 weeks after ERPC. Finally negative after 5 weeks and AF a few days later.