Suggest Treatment For Swelling On Knee

I seemed to twist my knee when rising from the table nearly 3 weeks ago and although it isn t painful now,it is uncomfortable and feels tight. It changes position every day - sometimes at the inside of the knee and sometimes at the back.Now it seems very slightly swollen.Previously for a few months I have had locking in the knee when I have stooped down and put it down to wear and tear ( I used to work in greeting cards where we were always kneeling to do the racks ). I have tried to cope without visiting the doctor but it doesn t seem to be getting better.