When i first read this, i was thinking of a swollen lymph node, but those are painful and usually associated with some type of infection. I'm not too sure what it could be. But definately watch it, and if it grows, make sure you see your doc. It is safe to keep an eye on it, You do not need to go to the doc right away. They will tell you the same thing, just watch it for awhile, and if it grows, go in, if it goes away, then good for you !! ahhaha..