2 week old sleeps 3-4 hours

During the day its every 1 to 3 hours of him waking up and eating at night hell go 3 1/2 to 4 hours between feeds is this okay or should i wake him every 2 to 3 hours still just paranoid because he had to go to the nicu after he was born for not feeding and his blood sugar dropped after going 6 hours without feed so ive been obsessed with waking him if he go longer than 3 hours but he eats alot of breastmilk when he is up , like up to 4 oz off the bottle and drains my boobs when he feeds off my breast