You didn't warm up properly and you probably injured yourself. I injured my left shoulder 4 years ago and it still hurts like hell even today,in fact I feel the pain as I'm typing this 4 hours after a shoulder workout. Don't fuck up like I did,you'll regret so much later. It will interfere with your workouts,I never feel the pain except when I train shoulders and go real heavy,even when I'm warmed up real good the pain is still there and I'll never be able to do anything about it,luckily it's nothing serious,just some pain that could be ignored once I got used to it but that's just me,make sure it heals properly,knee injuries can be devastating for legs,a injury like that can permanently screw you up to the point where you'll never be able to squat again. Get something for the knee. Don't try to squat or do anything that will put some stress on it,you will damage it even worse