This could be a torn meniscus, a loose body, or irritation of an arthritic knee. If your symptoms persist more than several days, despite rest, ice and judicious use of of over the counter NSAID's, I would see an orthopedist for a full evaluation.
MRI confirms a torn medial meniscus, possible torn PCL, and alot of fluid. Thanks ~~~Bill~~~
Having a MRI done tomorrrow and scheduled appointment with orthopedist in Toms River . Thank you for your quick feedback. ~~~Bill 2356~~~