Rule out the other causes. But as it is wth knee pain, you may be sitting with that leg crossed under your opposite buttock thereby creating pressure on groin and testis. Sit properly.

Needs evaluation.

Hi, As the pain is there since a week means, it may be a utetric calculi(stone) or epididymo orchitis . Ur problem may be a most common one i. e., utetric calculi . Take Tablet Diclofenac sodium tablet one /two per day for a week, with lots of water. Usually it will subside by 1-2 weeks (if it is a small stone). But be cautious and get an ultrasound done, if it persists.