my baby born at 36 weeks his birth weight was 2.28 now his is 88 days old baby (3 months) now his weight was 5 kgs 1. still he is not holding his neck 2. he observing only sounding and moving toys but doesn't try to hold the toys and doesn't try to play and chew he doesn't put interest on toys 3. he doesn't roll ( back to tummy) even he doesn't try to roll mothers plz tell me your experience i'm so worried about his why because his age babies do all but he doesn't do plz tell me when my baby do all these