When does it stop growing?

Maybe if you put it in me I can tell you...

Highly doubtful at 13. More like 16-20.

I'm 27 and mine stopped growing once it hit 15 inches. So I'd say it's possible for it to grow another 1 or 2 inches

I'm 19 and mine stopped at I'd say 7 1/2.

No, I've been growing the last 2 years a lot and I'm 16.

Typically the male body does not stop growing until you are in your mid 20s. With that said, everyone is different.

It sounds like you may have other concerns besides when your penis stops growing, so the best advice I can give is to talk to your doctor the next time that you go to see them. They can give you better answers than anyone on the web can.