this site is wonderful and I am sure you will become a regular part of the community.
I am happy for you that you finally get to bring home this precious little one.
BUT!
I must also say 4 WEEKS IS WAY TO YOUNG!!



do not bring this baby home so soon.he NEEDS to be with his mom and litter mates much longer and I surprised because he should still be nursing.this does not sound like a good breeder

to me.
PLEASE: search these post for more information,you will learn why this is such a horrible idea.but I am sure more knowledgeable people here will explain.
good luck