Babies can range from. 5lbs up to 13lbs
If doc isn't worried, don't be.
On my due date they told me my daughter was 10 pounds.. I went 10 more days after that before I was induced and she was 7.5 when she was born. I don't think they can really tell how much a baby weighs. I wouldn't worry to much, it all comes into place :)
With my daughter a day before i gave birth my obgyn was like shes like 6, 6 1/2 lb she was like yur little sou wont have big babies and my surprise the next day she was 8lb 6oz so dnt worry to much