it's normal for you.statistically there is a range in which most guys fall in,but notice i said most not all. you're only 13 so there's a chance that your penis will grow,but if it doesn't then that's ok too.
I do not read advertisements. I would spend all of my time wanting things
At 13 some guys haven't started puberty, while some may be most of the way through it. So you get a big variation in size. The guys who are big have started puberty early and are generally more or less at their adult size. You still have your growth spurt ahead of you.
It's perfectly normal! You will grow. I did!
Perfectly normal! trust me you will grow... I did!