How old is it? Do you know its weight? How are you measuring its length? Has it shed since you got it?
Some snakes grow fast, others take time and grow slow. Some snakies were meant to be shorter & bulky others longer & lean.
The only snakes I know that can be long and thicker girth wise are hybrids (such as creamiscles that have rat snake blood) or regular Okeetees.
If your not seeing a bump after 24 hours, stay on the 7 day feed cycle and bump it up to 2 fuzzies. I use to do that with my snake. Now remember, the more food that your giving him the longer it will take to digest!
But no worries...is normal.