HCG level at 5 weeks normal?

Kimberly
Had a little spotting so I went to the ER. I have bacterial vaginosis. My HCG Blood level is 4,668 which she said was a little low. They only saw the sac, no baby. I asked if maybe I was less than 5 weeks and she said I'm probably around there. Should I be worried? Maybe I'm 4 weeks?