hello, i'm also on week 4 of the C25k program, and i was experiencing pain in my left knee for the past week or so. What i did was i used kinesiology tape to tape up my knees, then i took a few days off from the program.After a couple days, my knee was feeling better, and after today's running (W4D1), i think its finally healed. i'd recommend you to get some kinesiology tape and look up how to properly tape runner's knees. But most importantly you have to take a rest until your knee feels fine, or you'll risk even more serious damage. All these info was from my own research and recommended by my cousin who is a physiotherapist, hope it helps!

As I was building up my mileage, I would get a "4 mile" knee pain that felt a heck of a lot like Runner's Knee. I stopped increasing my distance and didn't push the speed too much and I was able to run though it. I think that there's a very fine line between pain that can be run through and pain that demands time off and only you can make that call. Just be smart about it though, being sidelined for a few days, weeks or months this early on in your new-found lifestyle would suck.

As far as treatments, I got nothin' but I hope you're able to put this behind you quickly.

BTW, just got back from Kauai and the humidity + 9 miles darn near killed me!