Honestly if you research this you will find a wide range of what your numbers "should" be at this stage. If the doctor's aren't worried about it, I wouldn't be. The only way to tell if there might be a problem is if the numbers aren't rising properly. They should double every 48-72 hours. The numbers sound fine to me though. My numbers went from 150 to in the 3,000's in one week. So they more then doubled, they tripled. Talk with your doctor more about this if you aren't sure, but I have a feeling you will get similar responses to mine regarding this situation. Best of luck to you :)
http://www.americanpregnancy.org/duringpregnancy/hcglevels.html
If you go to this website you can see that there is a broad range for the levels. Your numbers are fine.
Congrats on your pregnancy!