What Causes Delay In Period After Miscarriage?

I haven’t had a period till to date. I had a miscarriage on 5th June and had D & C on the same day. Iwas pregnant of 6 weeks old. I had also visited to Doctor on 6 Aug, 2010 and checked pregnancy both blood and urine, which is negative. And did sonography is normal. As per my blood report my hemoglobin is 9.4. I don’t have any problem of pain. Please suggest me ?

Age : 36, Femail