Thanks for your query.
Your baby is having evening colic
which is seen in about 30 % of babies.
It starts at about 3 weeks of age and continues till 3 to 4 months of age.
There is nothing to worry till baby is accepting feeds,is active,gaining weight.
You can give colimex drops when required,massage
his tummy with coconut or olive oil in form of inverted u starting from right down/up then left up/down..
Mother should avoid gas forming food in her diet.
Wishing your baby god health.