HCG Low?

Hi ladies!

I found out on Thursday that I am pregnant! Took an at home pregnancy test expecting a negative and was shocked to see the line. Went to gyno that same night (they are open 24/7) and was told that my urine test was faintly positive and the doctor was shocked I had even tested because I was only 3 weeks pregnant. Nothing could be seen on the ultrasound.

They did blood work and told me to go again in 48 to make sure it doubles. I went this evening and was told at 3 weeks and 2 days I was at 40.9. Does that sound low? I'm so nervous because I won't have results and an appt until Tuesday afternoon.

Has anyone has a HCG test around 40.9 at 3 weeks and had a healthy baby?