Breastfeeding help..

Jami Lynn💜momma of five

My son is 3 days old and my milk came in today. He’s eating really well, every two hours for about 15-20 minutes. My question is what do I do about the fullness? After he eats, I get some relief but they’re still full feeling and are slightly painful. I read not to pump the first two weeks but I don’t know what to do about the fullness?