ANDY'S ANSWER: It's quite normal for a flaccid (non-erect) penis to be quite small. When erect, an average fully-developed penis length is between 5-6 inches. Of course that means that there wil lbe some people with shorter ones, and other people with longer ones. 

I would say that because your public hair has not fully come in yet, you are still at the beginning stages of puberty. Your penis will continue to grow until you are finished with puberty, which could be into your early 20's.