doctors do 2 different types of tests when checking HCG levels. Some will tell you, yes you are pregnant and your numbers have risen and the other one will tell you what your numbers are. Even though your numbers havent doubled, they have still risen, so look at that as a positive.

It is a good idea to head back to your doc tho, ask for another blood test so you know exactly what your numbers are.

goodluck! xo

ETA - i think when i went for mine.. to check the exact numbers.. it had something written on my blood test slip.. like quantitive.. or something.