Port seems large

I had surgery on 4/3/09 and my first fill on 5/05/09. I have lost 33 lbs. After having my first fill I haven't felt much change. The only problem is after I eat my port side feels like it is protruding out. I can feel a knot around one of my scar areas then after a while it is gone. Does anyone else have this problem and is it a sign of overeating. I'm probably eating 3/4 cup of food besides 1/2 cup. I have not been sick but I burp alot after eating but nothing comes up . Is the burping a sign of eating too much?