HCG levels at 6 weeks?

Can you write your levels at this point in your pregnancy (around 6 weeks)? I got a call from my doctor today saying my hcg was 6100 as of yesterday. Which puts me around 5 weeks according to them. I’m 6.5 weeks according to me (positive on ovulation date). Does this seem low to you? My first pregnancy at like 7 weeks, I was at 90,000. I’m really concerned about it :/