Miscarriage

I am 7 weeks 4 days and I had my ultrasound done and my baby does not have a heartbeat anymore. My baby is only measuring 6 weeks 4 days. I have not had pain or any bleeding. Since it has already been a week will the baby pass or will I have to get a D&C? Doctor said if I don't not pass it by next week they will do a D&C. Just was curious if maybe it would pass naturally?