Suggest Treatment For Pain And Weakness In Knee After An Injury

hit top of the knee while in a stationary bike pedaling as leg was coming up (the bike seat was too close so i hit the left knee on the way up). No swelling no pops. No pain at the moment it happened. a few days later noticed pain and somewhat weakness in the knee. I still play basketball with a knee brace once a week but walking and going downstairs results in some pain and i put ice on it. Not sure if there is a tear or a fracture or just a minor kneecap bruise/hit.. it's been about 3 weeks and it's about same in pain/weakness.