Sleeping longer 🤷‍♀️🤷‍♀️

My formula fed almost 12 week old has been sleeping better (no squirming/ fussing in sleep/ grunting ) since we started him on Similac Total Comfort .

That given, he takes approx 4oz per feed but for the past 3-4 days has been sleeping longer at nights (6hr+ at a stretch) with substantial sleep during the day as well. Also getting very playful & babbles for the same past 2-3 days.

I am beginning to worry if feeding pattern this is normal. He is an Asian baby weighing 5.2kg (11.5lbs) against 2.6kg(5.7lbs) at birth which is considered an “ok” weight gain & not poor .

Is this really normal ? Do they start sleeping longer so early ? Or is it just a phase ?

I was worrying that he doesn’t sleep ok with just catnaps during the day last week or before but now that’s changed to another extreme.