FTM . Baby is now 7w 5 days .On Formula milk.

Up until end of 6-7weeks was taking 90ml (one feed alone 120ml) once in 3 hrs .

For the past 4-5 days, his hunger & feeds hve been very erratic ... he takes 120ml & even 150 ml at times once in every 2.5hrs (gets hungry sooner). Is it normal / am I over feeding ? Or could it be something else ? He weighs 4.3kg now (2.5kg at birth).

No diaper changes. Otherwise has begun playing a lot .

Is this a growth spurt ?