What should I do about my sudden outer knee pain?

I'm not quite sure the full name of the symptom but its (something) horse which is a deep cramp from bending your knees, walking different directions(like bleachers), and etc. But since it hurt for 2 days I would try another 24 hours and stretch it out in the bed, and if it still hurts, contact a doctor because you might've broken something or made a serious injury.