Am I ballding at 17?

I am worried that I might go bald. My father was bald, but his father still had all his hair when he died of old age, and his brother started thinning only after 60. I have allways had thick hair, and it still is but the crown concerns me. Thank you in advance for your replies!

Looks like you might have receded a little ('mature hairline'), but your hair looks nice and thick. If I was you, I'd get on finasteride (and maybe minoxidil), then stop worrying about it!