My suggestion is - depending on your finances...

1.) if you have the finances to get a full vet check, then go ahead and get him checked out right when you get him - the stress of going into a new place and a vet check can be combined into one stress period instead of getting him acclimated, then getting him all stressed out again by taking him to the vet.
2.) if you have limited finances, then get the bp, wait until it poops and then take the poop to the vet for a fecal. Then you just observe your bp to see if there seems to be something not quite right physically. If you don't have much experience with snakes then you might want to get the book, What's Wrong With My Snake by Dr. Rossi (not sure of the title, but you should be able to google Dr. Rossi and snakes and get the proper title).
3.) if you have super limited finances, then just do the observation and have a completely reactive vet care. Might still want to invest in the book, though. Maybe somebody else out here has a better book to recommend.

Just my $.02.