Have been pulled over 3 times since I started carrying. Twice for speeding, once for failing to come to a complete stop at a stop sign. Only one officer acknowledged that I had a firearm on me. He first asked what the LTC was for. Then asked if I had my firearm on me and where. Once informed he just told me to leave it where it is. Thankfully I came out of all three instances with only a warning. Living in Mass where most people don't/cant carry I was expecting to be hassled but apparently that was not the case.
I personally think there is no need to inform the officer without them asking. It pops up as a red flag when they run their plates, I am sure they just assume I have a firearm on me whether I do or not.