I'd lay odds, however, that if they actually looked at you, and cared, at least one probably noticed. A concealed firearm, once the "tell-tales" are learned, can be fairly obvious to someone who actually keeps their eyes open.
Most of us don't even bat an eye. Heck, here in New Mexico, where we have open carry, it -still- doesn't cause comment, unless the cop in question thinks the gun being carried is particularly nice (one of the locals remembers me quite well, and I him, mainly because his EDC is a Kimber 10mm, and I noticed and complimented it.
) I've even seen people carrying openly in Wal-Mart, which, depending on who you ask, is a big no-no per NM law, because they sell alcohol; most of the local police, IF they say anything, will just remind the person "you really shouldn't have that visible here, mind covering it up?"Unless it's Albuquerque or Santa Fe. You're on your own there.