Having uneven breast for 4-5 years, is that normal? Am I now more prone to getting cancer?

Guys i know that it's not only me who has this uneven breast but having this after 4-5 years is making me worried. I am already 17 now and it's not changing and i read that breast development stop at the age of 19. Is there any chances for mine to get even and I've heard that having uneven breast has greater cancer risk.