3 week old preemie eating too much?

Hi mamas!

My 3 week 1 day old late term preemie (born at 35 weeks at 5lbs, 4 day NICU stay) has been breastfeeding exclusively (bottle fed as he won’t latch properly) and drinks about 4 - 4.5 oz of breastmilk every 3 hours. Is this too much?

He has about 7-8 wet diapers and poops around 5 times a day.

He is also around 6 lbs 10 oz now, so he’s gained quite a bit of weight.

Just want to make sure he’s not overfed...