My Bracket Is Embedded Into my Gum?

On Saturday I awoke to the left side of my mouth hurting, and noticed that my gum was swollen. A foul odor started to appear. I floss everyday so I know this isn't lack of hygiene, but anyway, while flossing today I flossed under the tooth that was causing the pain and odor and noticed that my bracket is on my gum. I accidentally broke the bracket off while doing this and when it broke there is an imprint of the bracket? I would really like to know why my gum just decided to do this uncomfortable action?