this is my first post here, and I wish it wasnt this question.

My BP is starting to look bloated twords his tail, and when I rub my thumb on his belly in that aria I can feel gass bubbles.
we have had him since the first of jan. he's only pooped an extreamly small ammount since we have had him and that was about a week ago in the tub.
he didnt eat for us till the first of feb and even then up till a week and a half ago the meals were too small for him(fuzzy mice then a couple of adult mice). last week and this week he was fed a sm rat. it's now been two days since this weeks feeding.

should I be concerned that he may be getting constipated? or is he just getting ready to poop?