I stepped off the end of my trailer and the inside of my leg slid down the end of the trailer. About 6 inches above my ankle to almost my knee. This happened about 2 weeks ago. 4 or 5 days later a dark bruise appeared near my heel, But I did not slide down the trailer that low. I have a knot on the side of my calf about 2 inches wide and 4 inches long that doesn't appear to be going down. I have alot of muscle in my calf because I move furniture for a living. Could this be a blood clot or something else?