C-182 Pilot reported a NMAC with a Helicopter while on short final to a non towered airport.

Narrative

Was on short final to Runway XX after flying a coupled approach on the RNAV approach. Spoke to another aircraft waiting to takeoff while I was still on a 5 mile final and told him he was OK to takeoff and he did successfully. While approximately .30 miles from the runway and approx 300-400; AGL Heard a radio call from a helicopter that was on a right base to Runway XX. Advised on frequency that I was a Skylane and a very short final and landing. As I looked up from my display I caught sight of the helicopter just off my nose to the right. Immediately added full power and banked hard to the left in a climbing left turn. Advised on frequency that I was going around and flew south of the field to re-enter a left downwind for Runway XX. We both landed without incident. The other pilot met me at my hanger and apologized for his late radio call. We had a discussion about proper traffic pattern entry. I believe that the nonstandard entry of the helicopter to the traffic pattern was a factor. I also believed that the lack of radio calls from the helicopter was also a factor. The other pilot even made the comment that this was a 'very quiet little airport and they didn't have to usually worry about other traffic'. Im not saying that I am a perfect pilot by any means but this type of complacency is what causes these type of issues. I am not a helicopter pilot and do not know all of the regulations that they are bound by for traffic pattern entry; however I believe a more standardized entry and flow would have stopped this from happening. I also believe standard radio procedures and callouts would have also resolved this.