Knee swelled up after leg presses

[N0xx]

Well, Its been almost a week. I felt a pull doing my second rep of the leg press, 120lbs and then it started hurting a little. Now my left knee grinds real bad and is a little swollen. I did a few light leg exercies yesturday. Stupied idea...so, i keep it proped up at night when sleeping because thats when it throbs so bad, try to stay off of it during the day.
So, how long should I wait to really do anything? Even elliptical work

[FunkDaddy]

Until after you see a doctor and he gives you the ok.