AF after MC

I had a natural MC on 8/14 at 5w6d. HCG was 74 on 8/17. Saw my doctor yesterday and he said that by 8/20 the HCG most likely was down to zero. He checked my cervix and uterus and said the cervix is completely closed and uterus is back to normal size. Per my doctor, I should get my period in about 4 weeks. When did you get your AF after your MC? Did you start TTC again that cycle?