Aw, ang dami naming moms dito na nag-alala about this too, ang drooling at looking up is pretty normal at 4 months kasi they're developing, but I'd really suggest bringing it up sa pedia mo just to be sure, lalo na kung may times na okay lang ang mata but mostly parang hindi siya nag-fo-focus. Better to ask them directly kasi alam nila ang development milestones, and they can check kung may underlying concerns or kung normal lang talaga siya. Paano naman pag may times na nakikita mo siyang okay, parang matinaw ang mata at tumitigil ang drooling?