Yeah given your last bubba was a 9lb'er I wouldn't expect you to be having a small baby.

BUT I wouldn't trust an u/s weight guess for the life of me. At 41 weeks I saw the OB who said "I don't think you have a 4kg baby in there" (my first was 4kg) and I said great, but I had to have a scan to try to postpone induction... the scan showed a 10lb 11oz baby. So the OB's at the hospital told me I had to have a c/s. I refused, went into spontaneous labour 2 days later & had a 4kg baby or 8lb 13oz. No where near what the scan showed.

To get a weight guess, the sonographer measures the femur bone in the baby. And uses a ratio with the head circumference. Not the amount of padding . So length vs head = weight guess. Which was inaccurate by almost 2lbs for me.