15 year old hairloss

[Coolsamme]

I dont know whether its a whirl or if nt hair is thinning.. I have always had standard Scandinavian thin hair but is this really normal for a 15 yr old boy?
My grandfather went bald young, my father got really thin about 30yr but my mothers side all have thick hair to this day..

http://m.imgur.com/fajtOtm,Xhkf47e,Ky9NNSs,Vl1ZQ9B