My baby is 1.5 months old. She is on exclusive breastfeeding. She passes urine well... passes litlle stools as compared to before. past week have noticed that she will make a gagging sound before every feed. as I introduce the nipple she will make a gagging sound and then will take nipple and start drinking and will start crying loudly while taking feed.this gagging sound she will make while sleeping as well. is it normal? we burp her after every feed. Do we need to see s doc?