Perplexing

So, I woke up this morning with an incredibly sore index finger. Of course my fingers are usually sore from playing the guitar (especially my chord fingers), but this is unusual. It feels almost like a bruise, or like it's swollen, which is not when callused guitar fingers usually feel like. They burn, they itch, they might hurt when you press right on the calluses themselves-- but this feels like I slammed my finger into a door. It doesn't look all that different (not swollen or anything), except that it maybe looks a little more red where it hurts, though that could easily be me making things up. The other weird thing is that the pain is asymmetrical, more towards my pinky than my thumb. I suppose it could be from playing too much (sometimes really thick calluses will start to hurt), but the pain radiates down the nail on one side, all the way to the cuticle. I'm probably going to try filing down the callus a little bit later, but I don't think I'll be able to play the guitar for a bit. The thing hurts when I press on the callus, or anywhere on the one side of my nail, plus when I press down on my nail from the top. I can even feel it as I'm typing now. I'm actually really confused about this; I'm usually pretty good at at least divining a source. I really don't think that guitar was the source of this, but then again, stranger things have happened. I suppose all I can do for now is wait, and maybe try my file later.
 
-Kal