There's swelling in the area?
I dunno if your patella or area got smashed it's likely that you had something happen there especially if the pain is still there. Whether it's a bone bruise, chipped articular cartilage, minor subluxing, etc. Could really be anything... too hard to tell IMO esp. since I'm not a med professional and this is the INternet.
Definitely does NOT sound like tendonitis at all.
It's getting better which is a good sign..., but if you're still worried you should see an ortho. Like seriously. Especially since you're shipping out soon.