This has happened about 4 times in the last couple of months. I'll be sitting at work and I'll get this pain around the bottom of my ribcage right up to my sides (above my gut, below my chest). It starts mild and gets increasingly worse. I don't have trouble breathing but it has gotten quite painful. It usually lasts about a maximum of 10 minutes and then its fine. Wondering what it could be. It has always occurred in the afternoon. I lift weights over the lunch hour, I don't know if thats involved.