Knee pain in runners is quite common due to the amount of pounding the pavement they can do over a number of years. Firstly, see a rehabilitation specialist such as an osteopath or physiotherapist to ensure it’s not something serious. Then, book a session with a movement specialist to help you with any misalignment issues and to correct your running technique.
Always warm up thoroughly through extended ranges of movement before going for your run.
Try swinging your leg backwards and forwards or doing short-range lunges. Doing fewer miles
on concrete and switching to grass would also help, as would changing one of your runs each week to a cross-training session or cycle, to lessen the amount of impact your knees are taking.