My right knee has been bothering me for a few weeks now. It's not really painful, rather a dull sorta annoyance. I don't remember ever injuring my knees, so I really don't see how I could have torn anything. I still lift like usual, and on leg days my knee doesn't bother me when I squat and leg press. My knee doesn't bother me all the time either, it seems like every other day or so, I'll feel the dull nagging come out of no where. Think I could have just strained it or something?