J.A.
Dear W.,
Please don't freak out, not good for you or baby. The important thing is that everything looks okay. Babies come in all sizes and the size they start is not always an indicator of how they will wind up! The important thing is that the baby is okay and developing reasonably close to the doctor's time table (sometimes they are wrong!). Try to relax and know that you still have a few weeks for baby to gain weight.