The vast majority of penile growth occurs during puberty.
You can't so don't worry about it.
Sizes will vary
I should hope you have hit puberty and theres something up with you!
its perfectly healthy. It is quite possible you haven't hit puberty yet, which will affect penis size. Also if that is 1 inch is non erect, the penis can "grow" as it is being filled with blood to be quite longer. There is also a chance that you could just have a smaller penis, which is still perfectly healthy
dont worry about it and when you hit puberty itll gror alot quicker
No, but a severe blow to the testes could effect the process of puberty.
Yes
The penis and testis grows in size, facial and pubic hair and hair under the arms, increase in height, shoulders get broader.
The size is correct and you already are in puberty. You will keep growing for a little bit longer yet. My friend Sheila who's currently 15, said her penis is approximatively 7 inches, and when hard 15. If your penis is as you say 3-4 inches at 15 you should seek medical attention immediately. Also, her penis is average size.
Yes, and it will continue to grow. You will have started puberty if you find your penis has grown to that size. Most boys start puberty around 13-years-old but it can start earlier or later.
this is because you either havent started puberty or your basically have to wait
When you hit puberty.