Felt knee pop. Hurts go extend and put pressure on... Top/outside of knee.?

Dislocated patella? Knee popping, pain extending from knee, and 'top outside of knee' sounds like a dislocated knee cap; it may spontaneously relocate, but there may be a ligament problem which holds the knee cap to the knee, which is why the 'pop'.
Complex. I am a functional movement specialist. The causes of knee cap pain are complex and we review some in the YouTube video listed. The causes will often not show up in a class knee exam or imaging. A functional exam in addition to classical is recommended. https://youtu.be/sVub-q5Wkqw https://www.youtube.com/watch?v=43Nh5aYwFnA https://www.youtube.com/watch?v=t6SXiDCMP3E Good luck and see someone.