On Monday I Slipped And Fell On My Left Knew

On Monday I slipped and fell on my left knew hitting a concrete curb. Have soreness and stiffness in the inner left side of my left knee. There is no swelling, but extremely sore and painful to touch. Do I need to get x-rays of the area or is just a major bone bruise. It feels fine in a horizontal position, but gets stiff in a sitting position.
Thanks