Not so great news

Ch
So I just left the doctor. I started spotting brown yesterday and this morning it was heavier bleeding and bright red. I've also been cramping pretty bad off and on. The dr said my hcg levels are around 300 and that it's pretty low. I thought I was around 5 weeks pregnant, but still don't know for sure. There was no fluid in my uterus but there was also nothing else that he could see. They sent me home with a threatened miscarriage and just said to come back if the bleeding exceeds 1 pad an hour. I was worried about this all along!! Anyone have a similar situation that turned out for the best?