What knee injury do I have?

I was at the gym and me and some guys were rolling/wrestling and practicing jiu jitsu. it's an MMA gym. This one guy wanted to go at full strength till someone tapped. We were rolling for about 20 minutes straight. For about 15 of those 20 minutes i was on my back and had the guy in a body triangle. Eventually we both stopped and called it a draw because we had to train with everyone else. The next morning my knee hurts. I felt zero pain at the gym or the rest of that night. I could still walk fine but there was pain when ever my leg was suspended, like off a bar stool or if my foot snagged something and pulled on my knee. i went to the doctor and she said give it a couple more weeks, it's already been 5, and I haven't done any training or running. She says it just sounds like i strained a ligament. Any other suggestions to what might have went on inside my knee. If u don't know what a body triangle is please google a pic, it's easier than me explaining. THANKS EVERYONE i really appreciate it, i need to get back in the cage soon