How did you know when your LO was going through a growth spurt?

My 2 month old stays asleep all day long (other than to feed) and is restless at night unless I’m rocking him. He’s also only satisfied when eating. He’s drinking 6oz every 3 hours.. is that normal? He went from drinking 5oz every 4 hours to 6oz every 3 hours in just TWO DAYS.

I will add, he does not spit up at all when eating this so I know I’m not over feeding him and he will refuse the bottle if and when he’s full.

I’m unable to ask pediatrician all this since it’s the weekend so I decided to ask here. FTM here so please don’t judge, I’m just looking to be educated from experienced mamas!(: