Replying to Knee

Today, i was bouncing on a tramp (which was wt and slippery). When I landed a jump, my right foot slipped, and my lower leg went left, while my upper leg went down. I have never seriously injured my knee before, so I was wondering about what pain level I should be feeling. It's a little swollen, but not too bad. The pain is moderate, not excrutiating, but not exactly comfortable. I can kinda walk, but not easily. Please let me know what you think.