Ay oo naman, normal lang yan! A few of us moms noticed din na ang babies natin ay may periods na mas tahimik, lalo na pagkapasok ng 4 months, sometimes it's because they're just focused on developing other skills like coordination o grabbing things. But since this is a noticeable change para sa baby mo, better check with your pedia just to make sure lahat okay lang, especially kung may other changes ka napapansin like sa feeding o activities niya.