my baby's birth weight is 3.5 . at 1 and half month is 5 .400 at 2 nd half month is 6.300 but in 3 and half month his weight is 7.1 only it's shows a decrease in amount of weight gain in 3 and half month.. he is now 3 month and 20 days old few days he refuses to drink milk. he is crying when ever I started to feed him. I give only breast milk.