Hi besempilot!
I read in a previous thread of mine that you have to formula feed baby, what formula are you using? Have you changed it since last week? With my LG we changed formula like 3 times before she was happy with it.
Maybe formula not filling him up enough or giving him a tummy ache..
Have you noticed a change in his poo

?
Hope you figure out whats wrong, its so difficult figuring these things out when they so tiny and cant just tell you whats going on.