Is is normal for there to be a significant bump on the inside of you mouth after a Monroe piercing?

I got a monroe about 3 weeks ago. I was a dummy and I cleaned it with hydrogen peroxide (yea stupid I know). When I went to get the shorter piercing, the piercer said it looked bad but it wasn't infected. Well when I had the longer one it'd get stuck in my teeth when I chewed and yanked around. I've noticed that the skin on the inside of my lip below the piercing is swollen and it's a little painful. Someone told me it was scar tissue building, and someone else said it was infected. Should I be concerned?