Idk guys what do you think

So there is a saying that if your newborn child is Advanced are doing more than what they should be doing at the age of they are fat the baby is making room for another one my son is 3 months old and he can already sit up by itself and hold itself sitting up without rolling over or tipping over hold his own head up, hold his own bottle , laugh , roll over on his stomach yes I am on birth control but as you can see birth control didn't work on my son as you can see he is also holding things in his hands now so ... what do you think.?