It really is never too late to start ballet. Many people start as adults, and younger adults, like you, sometimes even end up dancing professionally. I`d give it a try if I were you. Just find a good dance studio with certified teachers and try to learn the proper technique so you don`t injure yourself. If it is something that you really want to do just work hard for it and have fun while doing it. Be ready to see a lot of girls that are better than you, but don`t let that take you down, just try to improve and you`ll see that in no time you`ll be really good at it.