is my hairline receding?

[nutrisam]

Keep in mind...I never had a real prototypical juvenile hairline...I had 50 cent's hairline when I was 14 but a bit more recessed at the corners and lost that at 17. I am 20 now

pics are here...btw the top of my hair only looks thin cause I buzzed it down to a 1:

http://qkpic.com/d6136
http://qkpic.com/db391
http://qkpic.com/0ba88
....and how I look with hair grown out: http://qkpic.com/9eb9d


and here is me at 17:
http://qkpic.com/c32a9

I have a strong history of balding in my family. Both grandparents are bald. My father is bald...and All my uncles are bald on both sides, except only one of them has reached NW7...should I just take propecia as a preventative measure?

Am I a norwood 1/2/3?