There's really no such thing as "pretty." Everyone is unique in their own way and being called pretty or ugly is really just someone else's voice being expressed as an opinion. We, as a society, have built stereotypes and have unofficial rules that if you don't follow these, you are unattractive and displeasing to the world. However, being ugly is also really just being unique and yourself, and people are just scared to come out and change their point of views for the better. If someone really, truly, likes you, it's more for other things, like your personality or some similarities you both share.