When my son was only a year old my wife asked the doctor if we should be worried about his small penis.
The response was the typical - it's not a problem.
Not having gone through fatherhood before and not knowing my own growth rate nor anything about PE, I let it ride.
He is now in his mid thirties, I'm certain with a marginal unit, which I believe caused him to lose his first love.
He has publicly thanked me for his receding hairline, which is mine.
He is slightly taller than me at 6-3, built like a brick wall.
He takes after his mother's side of the family in regards to vision, I don't know where the small unit came from, other than the world of chemicals in which we live.
If I had known about PE in his developing years, I would definitely have helped him at an early age.
BJ