Is this normal , or infection ?

Brittany • Christian Mother , & wife ,baby number two Due march 27th??
Im over a week late , I'm giving AF two weeks before I test ! Every time I nurse my son and my milk lets down I get extremely nauseous .. Nothing has changed .. He's not nursing more frequently , I don't have any read places on my breast or anything ? Idk what think .. My nipples are extreamley sensitive it's almost unbarable to let him nurse ?