Oo, totally normal yan! Most babies grunt and stretch habang natutulog, lalo na kapag nagpapoop or nagpa-pass ng gas, ang digestive system nila pa lang nag-aadjust kaya the grunting sounds. Pero kung worried ka talaga or kung parang uncomfortable siya or nagitchy, best to mention it sa pediatrician mo next visit, basta para ma-ease your mind and ma-rule out kung may other things going on.