I Just Noticed That My Left Calf Is About An

I just noticed that my left calf is about an inch bigger than my right one. I do not have any pain in it and I do not know how long it has been that way. This morning walking in to work I mis-stepped on the outer side of my left foot. It is really sore, a little swollen and I limp when I walk because it hurts. I don't think one has anything to do with the other, but thought I should mention it. Should I be concerned?