I used to practice les mills but then started to feel knee pain, my test result came back - but I am still in pain, should I go back to sports?!

Knee Pain. It seems that rest has not helped your knee pain. After an appropriate evaluation you can try otc glucosamine / chondroitin sulfate & tylenol (acetaminophen) arthritis or motrin. Heating pads & pt also help. Rubbing analgesic creams or lotions around the knee can resolve it. You will need further investigation if your knee pain persists.