Nope. Never in my life heard of it being a britishism.

Edit: A downvote for proving an absolute statement wrong?

"Bloody" is used as a britishism. "Wee" is not, at least in many areas.

Those uses of "wee" (particularly the "urine" meaning) have been common in the US for far longer than I've been alive. Nobody thinks of them as "britishisms".