this knee isn't funny

recently my knee has been causing me pain and its grinding whenever i bend it. Now i find this to be very annoying esspecially because of my new exersice...i can't do the one leg because my knee clicks and hurts. I didn't do anything to cause this to happen so i am pretty much confused. I think i may ask Angie's opinion on it today! maybe ill have to see a doctor or get some x-rays. I am not sure, but i hope its not breakdown of cartilige because thats not good, i don't want surgery!