3 in at 13 big enough?

Answer 1

At 13, you are too young to even be concerned about your sexual growth. My word, you haven't even begun to go through puberty yet! You will continue to grow, as will your body parts, until you are 21 and, since your growth is pre-determined by genetics, you can't change it.

As for the penis, the size is determined by genetics. Medicine will tell you that you need to wait until 2 years after you stop growing to know what size your penis will be as an adult. So, you probably won't know that information until you are 23. For more info:
http://menshealth.about.com/cs/penisheal...

Just enjoy your youth and don't rush into adult matters. When you are old enough and mature enough, you will realize that it isn't the size of what you have but how good a lover you are.