Im not a LEO, but to the best of my knowledge, the answer is no, its not legal. In the state of North Carolina, even having a CCW permit DOES NOT permit you to carry a knife. CCW permits are strictly for handguns. So Id imaging concealing a knife without one would be even worse, or atleast equally illegal.
As for OC Spray or a Stungun....I'd imagine concealing one of these items wouldn't be illegal, assuming of course you're of legal age (18) which you are not, so you have a little while to wait.
Your best bet is to get a Pepper Spray keychain (when you turn 18 of course) It wont be considered concealed, yet you'll have it readily available if you need it.