Do you always pump after EBF to maintain supply all day?

Christy
I exclusively BF my lo and I am not sure if I am supposed to pump after every nursing session. I nurse on 1 side at a time becuase i have always had an over supply when i ep. Lo is almost 4 months,but I have only been ebf since 2 months. I was an EP until he could nurse full time after getting his ptt fixed. Now I only pump 1-2x a day when I make most milk. Other than that he feeds, but I have noticed he doesn't seem as satisfied during my afternoon early evening nursing sessions. Could this be becuase I am not pumping or is this normal. He was a big baby almost 9lbs and at 3.5 months he was 15 lbs. We go for his 4 month on friday. When he does drink for a bottle it is never more than 3 ounces and averages about 2.5? Is this normal for a usually ebf baby?