I have this weird nipple-like spot under my breast. I'm self-conscious about it. It's genetic, and runs in families. Guys get them too. It doesn't increase your risk of breast cancer, doesn't affect breast-feeding in the future, doesn't do anything, really.
Some people actually think it's kinda cool.
But if you're concerned about it, you can easily have it removed. Ask your family doctor about the specifics. I really wish I were thinner. It's hard to love your body when media frequently present the message that every physique should look a certain way. Yet genetics have given us all different body blueprints.