I am sorry for your loss. Nobody should have to go through a miscarriage of a wanted baby.
If things go on like this for another week without passing the tissue, there is a chance of developing scar tissue in the uterus that can impede later successful implantation. Given that you want to do a D&C and not wait, bug the doctor every day for a D&C date.
I let my body pass my miscarriage naturally. I was 6 weeks. I don't know if there is anything you can do. I started bleeding lightly which wasn't my normal period and then about the 5th day started getting heavier with worse cramping than I had been having.Thats about the time clots started forming pretty big. I knew when the sac passed cuz it was painful almost like a mini labor.