I am trying to find an answer here. I was shot by a .22 from some kind of semi auto pistol. It was night on a porch with 1 60watt light on. I rushed to the door

I am trying to find an answer here. I was shot by a .22 from some kind of semi auto pistol. It was night on a porch with 1 60watt light on. I rushed to the door after hearing my daughter screaming opened the screen to see a boy on the porch turn toward me with a semi hand gun in his right hand. He was 1-2 feet away.as I saw the gun coming around to shoot me. I knew I had to get the gun and reached for it with intense urgency. I saw a flash and felt something hit my upper chest HARD.and heard a 'pop' I remember thinking I failed horribly and was going to die. The next thing I remember I was chasing him down the street hitting him with the butt of the gun until all I was hitting him with was the barrel. ...much happened.. As I was calling 911 very distressed I told them I had been shot -- but looking down I could see no blood and no hole in my white cotton shirt.. The police recovered a .22 slug a couple feet inside the door to the left (door opens to the right) ..and no I have never owned a .22 and the slug in no way belonged on the floor. I later found what looked like a lead colored smudge mark above a button hole on my white shirt and my chest was bright red behind that spot. How the heck did that .22 not enter my chest? I had a thick cotton work shirt on with a tee shirt on beneath it -- But that is not enough to block a .22 in my experience. ?Anyone? This happened 4 days ago so my recollection is fairly fresh.