Hello S.!
I will say upfront that I have NO personal experience with your position (nor have I had a miscarriage), but if you are looking for the opinions of mamasource mamas, mine is that pregnancy is a natural thing. I personally feel strongly that miscarriages happen for a reason (whether we know that reason or not), and after the heartache has subsided, we try again and are eventually rewarded with a healthy baby.
However, if you are one to help something along (and there's nothing wrong with that!), then by all means speak up and ask your doctor for the pills that you want. Doctors can advise you of all your options, but if you know of options that are available that your doctor DIDN'T discuss, you should definitely speak up. You might also consider another doctor (if your current one is resistant to methods other than what she prescribes).
So, you need to decide for yourself what you want to do with your pregnancy (congrats!!! by the way!), and then you need to speak up and be open but firm in your discussion with your doctor. They have knowledge we don't, but no one doctor is the end-all-be-all answer to medical and ethical dilemmas. Some decisions should only be made by the patient.
I certainly wish you the best of luck, and do PLEASE keep us all informed of your decision, and of how your pregancy progresses.