Thanks for writing in.
It is quite possible that you sprained your knee.Take an over the counter pain relief medication like acetaminophen
after food. Apply pain relief gel like volini
gel or diclofenac
gel. Get some rest for 2 days. Avoid exercise for 2 days. Even after this period if youir knee condition doesn't improve, I would advise you to visit an orthopaedician.
Hope this helps.
Dr. Divya Kuttikrishnan