Time for a visit to the vet!
It's pretty standard to get a new puppy in for a checkup within 48-72 (ish) hours, especially if you have a contract or health warranty from the breeder.
Your vet will be able to provide more objective insight into the actual age of your puppy. Some puppies are naturally bigger, some smaller, some bolder, some quieter. This appointment will also allow you to have a conversation about vaccinations and de-worming.
If you've already visited your vet, please disregard. Welcome!