I wouldn't worry about it so much if I were you. I myself am 6'2 and I am only a few inches away from being as tall as my doorway. I also have a friend who is 4'11 and she always says she'd like to be at least 5'5. 5'8 is pretty much an ideal height for anyone especially someone who is a teenager.
5'8 isn't tall though, anything over 6 feet is. Then again, most boys go through major growth spurts when they are anywhere from 14-18. I think I have time, beside I have been going through puberty at a later age from what I've noticed.
I grew like 8 inches in my freshman and sophomore years and I thought I was gonna keep growing and be like 6'10" but I just completely stopped after 10th grade and haven't grown an inch since. Don't expect to grow too much anymore, you're pretty much done with that.
You never really know, I was reading about growth in boys and 60% of the time an increase in height during teenage years is caused by puberty, and the other 40% is from how you eat and how active you are. This summer I will start cycling a lot, and I already eat pretty well.
