I am about 7 weeks pregnant and went in for u/s, they could not see a heartbeat. They said I measured 7 weeks 1 day and hcg levels were at 31000. But Dr. thinks I will miscarry and told me I could come back in a little over a week to check again or schedule a d&c. I decided to wait because I have no signs or symptoms of miscarriage. Is a miscarriage inevitable?