Definitely go to your local sports medicine clinic. I've had knee problems with runner's knee and patellar band inflammation this Winter as well. Ice and rest are good until you can get there. Self diagnosis, unless you have a medical degree only makes things worst. I know that from experience
I can only relay what I've done to make progress...I don't know your exact situation. When I was in more pain, I went to a physical therapist weekly...I'm due for another trip as I've been achey this past week. I avoided doing exercises which require bending and stress on the knees...especially leg extensions, squats, lunges etc. If I could humanly avoid stairs, I did. I use jumper's knee bands for when I run or if I'm going to be climbing stairs, or walking up and down hills. It helps to keep my knee caps in place. I don't know if your's are shifting or not.
Good luck with it...if you have the means to go to a doctor and a physical therapist that's the best way to go. Ultrasound treatment on my Patellar tendon at the PT's office has been a Godsend.