Should I start the "big 3" or is it a mature hairline (pics included)

[Roger-rabbit]

I'm new to the site I apologize in advance if this is the wrong place to post this. I'm 21 within the last year my hairline has matured but I'm not sure if it's stopped or will continue to NW3. There's a history of balding in my family, I have two cousins in there twenties almost completely bald. However my dad's 55 with Norwood 2 and my moms dad didn't bald till he hit 50. I'm worried it's going beyond a mature hairline because the temporal hairline hairs seem to be miniaturizing (look at the close up pic) What do you guys think? Should I start a regime or and I being paranoid?

http://imgur.com/a/Qsf1x