Pomeranian puppy uglies?

When does the puppy uglies stage usually begin or better when did it start for your little pom? I have what I think is a 13 week of old male and he isn't losing or shedding any fur, he is actually super fluffy although his legs and tummy are a bit short, but he is definitely growing a lot of long adult fur and has been for a few weeks now. Does this mean that he's going to get into the ugly puppy stage soon? Will he lose all his fur? I live in Texas and is super hot but he's inside 98% of the time.