Formula versus breastmilk!?

So my almost 7 week old gets breast milk during the day and formula at night. During the day I can get him to sleep almost 3 hours which is what he goes between feedings. He eats about 3 1/2 ounces.

At night he gets formula but is only going to hours between feedings.

I think he is currently going through a growth spurt so I don’t know if that has anything to do with it but would increasing his formula help to get him to sleep longer or is it just a phase?

Not sure if there’s a difference or if others have experienced better sleep with one versus the other!?

My little nugget. 💕💙👶🏻