ANDY'S ANSWER: You are not even remotely finished growing yet. Most boys stop growing between the ages of 18 and 22. When I was 14, I was probably very close to your height and also worried I would be "short" all my life. Now I'm over 6 feet tall, and the rest of me has also grown proportionately.
Your penis will continue growing until you are completely finished with puberty... usually a 5 year process. An average erect penis size (once fully developed) is between 5 and 6 inches. That means that some people will be shorter and some will be longer. A shorter penis absolutely does not prevent you from having sex or from being able to get someone pregnant.
Although it is hard not to do it, it's really unfair to be measuring your body's development against other people's development. Everyone grows at their body's own rate. I'm going to bet that between now and next year you go through a growing spurt that is going to bankrupt your parents trying to keep you in food and clothes.
Below is the recording of Andy answering this question.