Question about sudden edema in finger then bruising

Yesterday I wasn't doing anything when all of a sudden my ring finger grew with pressure pain like I just popped a blood vessel. It lasted about 1-2 minutes and then started to swell up and get hard but only in the middle of my finger. The next day I had a large bruise and it's still a little swollen. I might recall this happening to me before but I'm not sure.

Could this be from my medication? I take zithromax 500mg a day, Flagyl 750 a day, and Questran 1 packet a day. I also take supplements etc.

I tried to take pictures but the color doesn't contrast well on my webcam. :/
http://s577.photobucket.com/albums/ss214/ask00000/Finger/

Has anyone else had this happen or know what it indicates?