Inat ng inat

Hello mommies, my daughter is currently 4 weeks old dati ko pa napapansin sakanya everytime siya nagsleep, grabe siya umunat hanggang sa minsan nagigising siya para tuloy nauudlot ang tulog niya. Is it really normal for a baby na sobrang mag stretch at mag unat? Minsan may kasama pang utot. Nabobother kami ni hubby baka it has something to do inside or within her body. Sana may makasagot po. Help out a new mom. Thank you!!!!