She straining, If yes?. Don't worry about the straining, normal phenomenon in exclusively breastfed babies"

Colic is common. It usually starts a few weeks after birth and often improves by age 3 months. By ages 4 to 5 months, the majority of babies with colic have improved.
When to see a doctor
Seek immediate medical attention if your baby's crying could be the result of a fall, injury or illness.

You can keep them in the car seat put in an upright position if you are too tired or busy to carry them that long...others can help too.....sometimes that may not work and ....but we will do that only if it so bad and not allowing the baby to gain weight....please see your paediatricians for further management at that point