My LO is 3 weeks old. I was told to feed every 2-3hours. But if baby sleep more then 3hours will you wake them up for feed or let them sleep till they cry for milk ?

Hi, I do not think you should wake up your baby to have feed. If your baby is hungry, he will on his own wake up out of hunger. Babies generally too take small naps and if your baby is taking longer nap, you must check that otherwise he is doing fine or not. If he is not having any physical ailment as such then longer sleep is good for his health. Just make sure that his nappies are dry and he is not in wet diaper for too long, as in that case you will have to change his diaper and in the process he will get awake. But that is fine. Also, if the baby is healthy and have no problem, then longer naps are perfectly fine.