Size 2 nipple at 4 weeks

My LO is 4 weeks today. I noticed over the past couple days that he was suddenly taking much longer to finish his bottle. He was fussy while eating, and would also fall asleep and not finish (but still wouldn’t be satisfied). His dr. Browns bottles also started leaking a TON.

All of these things pointed me in the direction that he was ready for the next sized nipple. I was weary because he’s still so young, but I suppose every baby is different?!

Today we tried a size 2 nipple for the first time, and what a difference. He stayed awake and finished his whole bottle in ~25/30 mins (rather than 45/1hr)! His bottle also leaked waaaay less.

Anyone else experience this at an age this young?