HCG LEVELS AT 600 & BLEEDING

Last night I went to the ER cause I had bad cramping and started to bleed bright red (still bleeding but not heavy). They did my US and vaginal US and saw nothing not even the sac. I thought I was 6 weeks but they said I might be earlier cause my hcg levels. I have to go back in to do blood work on Thursday . Has anyone gone thru something like this and had a healthy pregnancy?