Yesterday, while sitting, i started to feel a horrible shooting pain under my knee cap, it went away about a minute later, then returned for the same duration later in the evening at least 2 more times. It just happened again. I am 35, healthy, bit overweight, but I'm very active (I'm a firefighter), I have had no trauma to the knee and am experiencing no stiffness or restricted movement, just random, horrible shooting pains...