Help? Small baby

Went to dr for ultrasound supposed to be 8 weeks tomorrow according to my lmp but I measured 6 weeks and heartbeat was so low couldn't catch it on the US but could see it flickering. My dr left had me see the Midwife and she said with these two signs most likely will MC.  trying not to stress because there still could be hope? This happen to anyone else before?? Any good out comes?