If there are absolutely no signs of inflammation, like pain/ swelling then you may wait for a few days before getting youself evaluated , however if you have any pain/swelling/ discomfort, then this could be indicative of a knee pathology. The symptoms are not specific enough to localize the problem however a mensical injury is a possibility,
Please remember to accept the reply if you find it useful. A BONUS and a positive rating would be duly appreciated,
regards
Dr. Gupta