Bang On The Knee Caused Continuous Clicking Of Knee Cap, Simple Contusion. Treatment?

While playing football recently, I clashed the lateral portion of my knee against a defenders knee brace in such an angle that i felt my patella shift. Although it immediatly hurt, I walked it off and continued playing. Within the following 48-72 hours my kneecap would click out of place when standing up causing slight pain. I feel like this may be a simple contusion, but the concern of my clicking kneecap is causing me to seek further advice. Main pain is occuring on the lateral aspect of my patella(VMO and superior patellar tendon/quad tendon).