Hummm i looks like you going to have a big baby.
The weights of babies are just an estimate and can be off by as much as 2 lb. 5 lb is the 'average estimated' weight for 34/35 weeks but you won't know for certain what your babies weighs until they are born. It doesn't necessarily mean your baby will be big.
I had a scan earlier this week at 37+3 baby weighed 6lb 14oz x