I Twisted My Knee This Morning At Work, When It

I twisted my knee this morning at work, when it happen I felt and heard like a pop. After I walked around a little bit it felt better so I continue with work, after my lunch I started to feel pain in the knee again. A couple of times I thought that knee would not support my weight. I feel most of the pain in the knee cap area and on the back and side of the left knee.