Hi Sonam please stop worrying about the weight part, for 3.5 months 4 kgs is good. And only breast milk till 6 months.

<a href="http://app.babychakra.com/article/2555">Height And Weight Chart: An Easy Tool to Monitor Your Child&#8217;s Health</a>

<a href="http://app.babychakra.com/article/2623">Understanding Baby Weight Gain</a>

Baby is 4 months old so breastmilk only.U should take healthy diet,more liquids n eat properly as baby is on feed

My baby boy is 3 months and 20days old.but still he is so weak.his weight is only 4kg.he is totally on breastmilk.wht i do to increase his weight.i m worried.nyone plz suggest me