I had pretty much the exact same thing happen to me in mid-late Jan. I don't have knee problems so I thought it was a bit weird when i'd get this pain on the inside upper part of my knee (kinda half under the kneecap and half out). I got nervous too after I read about all the knee problems that can occur. It never hurt to do anything but bike. I could lift weights, run, walk, go up and down stairs no problems. The pain would start about 20 minutes into a ride. I tried pushing through it during a 2.5 hr ride and it just ended up hurting through the weekend. Anyway, I didn't ride for about 2 weeks, just lifted weights and ran since those activities didn't seem to affect it. After the 2 weeks I nervously got on my bike, started pedalling and the pain never returned. I thought I maybe had VMO tendinitis but now I'm pretty sure it was from slamming my knee into the corner of a cabinet. The pain started the day after I did that, just didn't connect it b/c I've hit my knee many times before. But this time the cabinet corner went right into where my VMO connects with the kneecap. I'm no doctor, but I'd say don't do any activites that aggravate it for at least a week, keep some ice and pressure on it and pray for the best.