I'm sure you won't have any problems, particularly if you have a normal type of sporran. Billy Connolly seems to go backwards and forwards to America with a badger sporan. I think Customs are a lot tougher in America when it comes to certain items like seal fur and wherever you go ivory is a no-no unless you can prove it is older than the ban (e.g. bagpipe fittings). And pack your sgian dubh in your hold luggage or it is likely to be confiscated.