Wah, clever baby you have there! At 3+ months, some babies memang start showing those milestones early, tapi yours is definitely on the speedier side, most don't angkat kepala so tinggi or niara properly until 4-5 months, so you're doing something right! A few of my mum friends also had early developers, and honestly the thing is to just enjoy the phase because before you know it they'll be crawling everywhere and you'll be chasing them like mad, hehe.