Have you had a portogram? I had pain in mine with every infusion (I had a 9 year old port) for about four months. Finally my Doctor ordered a chest X-ray and told me I had pneumonia and I had a course of intravenous antibiotics. I thought that was odd as it only hurt when my port was used, I had no fever and no funny breath sounds. Fast forward a couple more months and I still got the pain and insisted I have some investigations so I had a portogram which showed my port catheter had cracked and was leaking into the chest cavity. I had it removed and replaced in X-ray a few days later. I havenít had a problem since then.
I hope you get answers.