Yes, you must disclose if you are concealing a firearm. Even if you are OC'ing and concealing a firearm you have to disclose. One dosen't negate the other. If being approached by an officer and you are concealing even before you say hello, you should tell him/her that you have a Concealed pistol. There is no penalty for disclosing. And should you not disclose the penalty is a civil infraction and not a crime. 6 month suspension, 500$ fine and your gun can be confiscated from you. You get the gun back, it will be held at the PD or jurisdictions equivalent.
Hope that helped!