Five days ago I tripped over some wires and fell on a carpeted surface. At the time, my knees seemed to be the only painful part. I don't remember landing on my hand/arm, but on the third night after the accident, I awoke to mild throbbing in my forearm. There is a visible soft bump/swelling on my inner forearm (up from my thumb). Since it took several days to develop and the pain is intermittent just around the swollen area, is this something I can safely ignore?