What is wrong with my knee?

Okay, during xc running season I had knee pain and was diagnosed with patella femoral pain. An MRI showed inflammation, but no tear. My knee started to feel better. In march i went on a missions trip to Honduras. While playing soccer, I was slide tackled. My knee twisted funny, and I thought I tore something. I decided to give it time to heal, it's been about 90 days. My knee still hurts on the inside side of my left knee ( right side of my left knee). The pain isn't debilitating but it is uncomfortable and I could not run more than probably 1/4-1/2 a mile or maybe less without feeling pain. It feels tight and sore, but it calms down when I am sedentary. I have made an appt with my dr for next week, but wanted some insight to what this pain could be? Thank you in advance:)