9 Year Son, Swollen Lymph Node, Stomach Pain. Should I See A Pediatrician?

My 9 year old son has a swollen lymph node on the right posterior side of his neck. He has had this in the past. The first time I saw it I took him to his pediatrician who thought it was benign and to keep an eye on it for a few days. If it didn't resolve in a few days to come back. It did get better so I didn't follow up. That was about 5 years ago. He has had the same thing happen over the past 5 years and it usually goes away in a few days. This time it has been swollen for about 2 weeks. He has been complaining of stomach pain on and off usually a little while after he eats but I don't know if that is related. Other than that he is completely fine. No fever. Plenty of energy. Sleeping normal. Not sure if I should call his pediatrician. I hate to over-react about anything.