Pomeranians

hi harley is my adorable pomeranian pup he's 4 months old & he is going through his puppy uglies. but im kind of confused by the way their hair is suppose to grow out. the first time i saw him, at the breeders house, he had no hair only around his neck. i just picked him up tuesday and he is much fluffier. but i want to know if the really soft textured fur is his undercoat? his top coat is coming in around his neck but i noticed that there is no under coat under that hair.help please:)