my baby boy is 4.5 months old. his birth weight was 3.3kg and currently his weight is 5.7kg. earlier I used to do breastfeeding and gave top feed 2-3 times in a day and his weight was increasing accordingly. but since 20 days I stopped giving him top feed as per doctor advice and was doing exclusive breastfeeding. and in this duration his weight didn't increase at all. any suggestions?