If it is lawfully being carried, I wouldn’t bring it up. Of course, if it’s illegally being carried, I wouldn’t bring that up, either. In fact, unless they specifically asked about “weapons” – I wouldn’t bring it up. You’re not offering up the lawfully carried spare tire or box of Kleenex, are ya? You don’t have to bring it up, so why escalate something? Now, if they were starting a search, and had not asked you about having any weapons – you may want to bring it up then.