Filler at 20 Years Old, Too Young?

I'm a 20 year old female and I dislike that my top lip lacks volume. I find in pictures that my top lip is barely noticable and almost disappears. It is not as bad if I am not smiling very big, but it still bothers me. I want a plump pout. Not too much- I don't want to go overboard, but I would like to notice my lips! My question is: Am I too young to get a filler? I'm afraid that my dermatologist will judge me or think it is unneccesary at such a young age. Thank you very much!