Hi, I've been having a similar problem in the same knee, i see a sports massage therapist and he tells me it's a tight IT band that runs from you hip into the side of the knee and its rubbing on the bone. I've not run for about 3 weeks due to this and other commitments, but been out this morning and after a mile it started again. He told me if it does start to stop running straight away as it won't get any better carrying on. I have a roller that I use to roll out the legs, and stretches to do. It's just a guess but maybe you have the same injury and would advise seeing a therapist for it!! Hope this kind of helps. I've come on to see if anyone can give me some more advise on how to tackle the problem, without having to keep paying out for a therapist!! Any advise would also be appreciated. .