Sprained ankle

I ran 2 miles on this roads this evening.  After getting home, I was stepping in the shower and noticed that the inside of my right ankle was dark purple and slightly swollen.  Sprained?  I don't remember doing anything to sprain it and did not notice any particular pain when running.  It is about 12 inches below the bruised and swollen leg from the logging accident a few days ago.  I wonder if the injuries are related.  Oh well, keep running.