Aww, baby cough memang sakit hati kan! At 30 days old, sebaiknya check with your pediatrician dulu ye, especially if the cough is persistent atau ada phlegm, newborns ni kena monitor closely. A few of my mum friends said elevating baby's head slightly while sleeping helped a bit, and making sure the air isn't too dry in the room also makes a difference, tapi really confirm with the doctor first to make sure it's nothing serious. Hope your little one feels better soon!