This is a normal condition and it is scientifically referred to as gynecomastia. It occurs as a result of normal hormonal changes and it is quite common at puberty. You should consult a doctor for advice.
Once I heard of a surgical procedure done to remove the glands that causes breasts growth in men. Go to google and research it. Other than that start doing push ups and bench pressing to develope chest muscle mass.
My son had this condition and he was very skinny. The doctor said it would go away and it did. Stay away from anything that contains soy! Soy turns into estrogen in the body. Also, watch the meat you eat. Make sure it wasn't treated with hormones. Your body will soon stabilize and your chest will look like all the other guys.