Is my wrist broken/fractured?

Today, I was skateboarding and I did a trick (for you skaters out there, it was a switch backside bigspin) and I slipped off my board, falling straight down on my wrist. It hurt quite a big, but I didn't noticeably see a broken bone. Later I then looked at my arm, because it hurt, and saw that a small bone right in between my radius and ulna on my left arm is larger than my right, somewhat bulging out and is constantly in pain, especially when I touch, I was wondering if it might be broken/ fractured/sprained/ or any other type of injury. By the way, the mobility of my hand was not affected.