If you have pain, redness
and swelling on your knee, it might be a fracture
But if you are having these kind of sensations, it might be possible that you have got a ligament tear, or a muscle injury
Best thing is to meet an orthopedician as local examination will help in diagnosing the problem, and if required an imaging would be done.
You may do fomentation, may apply local pain killer and anti inflammatory gel readily available in the market, under your doctors supervision.
Get well soon