Bump on lip

Carly

My son is 2 weeks old and breastfeeding successfully. The only issue I’m really having is I notice sometimes he gets a bump on the middle of his top lip. He latches really good most times but sometimes gets lazy when he’s tired and doesn’t get a full enough mouthful. Am I doing something else wrong? or should I be worried. It looks almost like a blister but doesn’t seem to bother him.