Im 15 and im 6'2 lol im a beast....

5'9" isn't bad at all!

I'm 19 and im only 5ft9... Don't worry about it.

Don't count your self out just yet a friend of mine just grew considerably after his first year of college, what is important is if you developed early or late, if late depending on your genes you will grow, but it is less likely if lets say you were about that or a little shorter, I'm 5'11" and 17 but I was short in middle school, I didn't start developing until the beginning of freshmen year so I hope I grow at least 1 more inch but my dad is 5'10" and my older brother is 5'11" so I'm not getting my hopes up, but genes are important check grandparents and uncles to see what is the general tread your family follows, and if there is one tall guy and the rest are leveling off at 5'9" it might just be best to accept that you aren't 5'4" and have to look up when you kiss your wife.