Im A Teenager (17) And I'm Not Sexually Active At

Im a teenager (17) and I'm not sexually active at all. I have noticed that my labia minora has become darker and rougher. Little tiny bums are felt like a cats tongue. I though maybe it was a yeast infection so I treated it but hasn't gone away. It doesn't itch, hurt, burn, or cause discomfort. Is this normal? I've also been under a lot of stress due to college and high school classes.