I was out to luch with co-workers and all of a sudden something was bothering me under my top lip. When I got back to the office I looked in the mirroe and found a small "bubble" under my top lip. Any ideas. My coworkers thought it is related to an infection

I don't think infection. Infection would manifest itself in an entirely different way. What did you have for lunch ? It could have been a food particle of some kind. Don't look for trouble where there isn't any. Think first.

It's gone now... but I'm just curious. It was not a food particle. It looked like a small clear bubble

What you had was probably a mucocele and is usually caused by trauma. There is nothing to be concerned with as they are harmless.

Thank you flossie!