Male Pattern Balding And Body Hair

I’ve been learning a few things about Male Pattern Baldness but one thing remains unknown for me ( and for scientists also , maybe).
I am a 19 years old dude who has growing body hair (A LOT) , even in the back.
By my mother’s side no one lost his hair, but in the family of my father every man lost his hair .
My father in his early 20′ , my grandad not , why?
My grandad had no body hair, my father is a monkey , coincidence? I am sure i am going to bald in my nearly future but doctors still deny this correlation.

Body hair and scalp hair is not related. You can be bald and have lots of body hair. You can have a full head of hair and have lots of body hair. There really is no correlation between the two and balding.