Sounds like a tear or inflammation of the quadriceps where it attaches to the patella. I can't give you any medical advice but my amatuerish guess is that it will take weeks or months to fully heal, since tendon and ligaments injuries seem to take a long time. When I got tennis elbow from hoisting tents and sleeping bags into the roof carrier of my van in 2002, it took a year to heal, and when I got a sore knee (a little more to the outside than what you're describing, but also at the top of the patella) from biking in winter boots on a bike with a frozen shifter, it also took months to get better. However, in the second case, I found I could minimize the discomfort (and hopefully avoid aggravating it further) by readjusting seat height to compensate for the chunky soles on the boots, and spinning furiously in lieu of mashing.