It sounds like you have a sensitivity in your knee collateral ligaments. these ligaments exist on either side of the knee (lateral and medial) and prevent the knee joint from falling out of place during sudden movements. You need to protect the joint with an elastic bandage to offer support to the ligaments. I would also advise taking it very easy with sport in the meantime. If your knee hurts, it means there is something wrong with it. You need to allow your ligaments to heal either through complete rest or reduced activity and protection with a bandage. If you choose to ignore an injury it will get worse overtime. Is there swelling as well as pain in that area? If there is swelling, then you need to elevate your leg above heart level while resting it and apply compression to it with a bandage. If it is just minor pain then you might wish to try taping the area that hurts with kinesiotape, This is stretchy tape that allows movement whilst offering support to your ligaments.