Unless your puppy is a hairless breed, he was born with hair. It takes eight to nine weeks for a litter of puppies to develop in their mother's womb. During the last month of development, Pal undergoes a lot of change preparing him for life, including getting his first coat.
Inside Growth: The First Month
During your puppy's first month of development, he went through a lot of changes that put him on his way to looking like a dog. The first two weeks of her pregnancy, little Pal was a mass of dividing cells, eventually entering Mom's uterus during the third week. During the fourth week, a puppy can grow from less than 0.25 inches to as long as 0.6 inches. Though they're still tiny, an experienced vet can palpate the mother to confirm she's pregnant. At this point, puppies in the uterus are most susceptible to defects.
Real Change: The Second Month
Into the fifth week of pregnancy, puppies begin to resemble dogs. Whiskers, toes and claws begin to develop and gender is determined. Little Pal began growing his hair around the sixth week of pregnancy, and he was properly proportioned by the next week. He likely started moving around during the seventh week, and by the final days of pregnancy, he wasn't a fetus, but a puppy waiting to be born.
Not Done Yet
Unless he's a hairless breed, Pal was born with a soft, downy coat. Despite that fuzzy fur, he still had plenty of growing and developing to do. As a newborn puppy, he didn't have his sea legs yet. Pal couldn't see or hear, and spent most of his time sleeping. When he wasn't snoozing his first week or two, he was nursing from his mother, who also had to stimulate him to make him poop and urinate.
Getting Ready to Grow
When he was about 2 weeks old, Pal's development accelerated, putting him well on the road to adulthood. His eyes opened in his second week and his ears opened around the beginning of his third week. During his third week his teeth began to appear, he learned to poop and urinate on his own and he began to stand and walk. His sense of smell began to kick in at this point, and he became aware of his brothers and sisters. By the end of his first month, he became a playful guy, interacting with his litter mates and learning to eat and drink on his own. That's a good time to introduce a puppy to the grooming process, spending time brushing his puppy fur and handling his paws so he'll be amenable to having his nails clipped regularly.