Ran/walked 3 miles

My wife and I were out early (for us) this morning, about 9 am. It is a beautiful day, and we enjoyed being outside. The temperature during our workouts went from 49 (F) at the beginning to 67 at the end. My right leg felt fine so I went for my normal 3 miles. I did notice, though, that my right knee is swollen, and that might be the result of what ever has been causing my right quad to be tight. I noticed yesterday when kneeling down to pick up leaves, and again this morning when I knelt down to do my 10 pushups, that my right quad was tight and slightly sore. I'm being more diligent in doing my stretches, and I hope the stretches strengthen my quads.