What Could Swollen, Sore Fingers After An Injury Indicate?

I hit my right finger a couple weeks ago doing a box jump at the gym. It's still a bit sore and some bruising can be seen. However, a few days ago, I woke up to that finger and the middle one to be swollen and it felt like I had hit them both. However, I know for a fact I did not hit the middle finger. Any ideas why the middle finger could be that way?