Just wanted to say I'm sorry you're going through this. I've never really waited for an m/c to pass on its own, but I have had more D&Cs than I care to remember. It usually takes me about 6 weeks to get my cycle back.
On a positive note, although I've had 10 mcs since my DD, I am now 27w2d, so there is defiinitely hope. Good luck to you!
I'm so sorry for your loss. May I ask how far along were you?
Do you have an ob/gyn? I'm very surprised your doctor did not do any follow-up work to make sure everything passed. With miscarriages, usually doctors want to ensure that all material is out because anything leftover in the uterus can cause complications. (I had a miscarriage at 17 weeks.)
I think some blood work is standard to make sure your hcg levels go back down to zero. Check with your doctor, or find a reputable ob/gyn if your family physician is not being helpful or proactive. Best wishes.