Sorry for your loss.
I have not experienced the same situation as you, but you might find this website useful:http://www.pregnancyloss.info/waitingforaf.htm
In my case, I had my first M/C and D&C in March 03, my A/F did not return at all. It took until May 04 before I could make sense of this.
There is a rare condition called Ashmans Syndrome. After having a D&C there very rare chance that the uterus walls and cervix can adhere together.
Polycystic ovary syndrome can also cause the absence of A/F. PCOS can often be masked by the pill, when you stop taking the pill TTC your periods make become irregular or non existent.
In my case, it turned out that I had both problems.
Only my cervix (not my whole uterus) had closed up and this was rectified with a operation in early June 04. I was also diagnosed with PCOS which is being treated with a drug called Metformin.
My A/F finally came exactly 28 days after the op - 28 June 04 - it was a long wait.
I then conceived straight away. Devastatingly, my 2nd little bub didn't make it either - its little heart stopped at 7.5wks, I found out on Tuesday (at 9 weeks) and had the D&C that night.
I will be keeping a close eye on the return of my A/F though.