Knee Pain?

For the last 5-6 months, my right knee has been hurting when straightened after being bent, or when just when it's bent. The pain is especially noticeable when I wake up in the morning. It's occurring more randomly now; it hurt more the first 4 months after I first noticed it, although it tends to hurt more after I run (I do track and field) or when I'm going up/down the stairs. (BTW, before and after running, I always stretch.) Also, I don't know if this helps, but I can bend my legs in really weird positions, which I do often (other people find this weird), so does this contribute to this pain? Oh, and my knee (right) seems slightly swollen? Compared to my left knee, which looks normal (I guess), my right knee is larger and possibly swollen. Thanks a bunch for any suggestions!