About a year ago, I tried to start running, I somehow hurt my left knee. It didnt hurt too much at the time, but off and on it hurts, it hurts to push on my knee- like my dog ran into me the other day, hitting my left knee pushing it backward while i was standing..very painful! It hurts on the outside joint, now it is swollen and i feel pain on my inside knee joint also?? WHat could be wrong?