Sporadic Knee Pain Behind Knee Cap?

Well first of all runner's knee and move go-er's knee is the same thing. It is called patella femoral syndrome(this may also be the culprit but it doesn't sound like it though) it is also called jumper's knee, swimmer's knee, etc. Anyway what you are describing sounds wonky it could be that your knees are just sore, but the only way to be absolutely sure is to have them examined.