No menstrual cycle 4 months after a D&C

I had my second d&c in 6 months on 12/4/09. After my first d&c, I got my period and returned to a regular cycle after two weeks. I easily got pregnant again even though I suffered a second miscarriage (I was told the miscarriage was due to a severe birth defect).

I did not receive my period after the last d&c. I called my doctor after 45 days and he told me to call back after 60 days. I did and was given Provera (10 mg for 5 days). He told me to call after 3 weeks if I did not get it. I did and was told I have to wait for 30 days and will be given another dose of Provera if I do not get my period. I asked if it could be scar tissue being a possibility and he snapped back saying he has never had a surgery resulting in scar tissue (which was not my question).

I am very frustrated and need some guidiance. Is this normal to wait so long to get some reasons for the cause of not regulating my menses?  Is it normal to wait 4 weeks after completing the first round of Provera before seeking different reasons? Is there another course of action I should be asking my doctor about? 

 I have reached out to another doctor but have to wait 7 weeks until the appointment. I am so nervous imagining it could take up to 5 months from my d&c to get any idea as to what is wrong! Any adivce would be very helpful to me!