Why don't my nipples pop out?

I am 13 and this may sound weird but my nipples haven't yet popped out and it's just. Large pink circle with spots on it?? The only time that they will poke out is when I am cold/wet or when they are touched. I can't understand why they haven't popped out yet as most of my friends have. And boys are always saying things about girls boobs are ugly If they have 'burger nips' which basically what mine are which makes me feel uncomfortable and embarrassed and I want to know why they haven't poked out yet and if they will, would really appriciate advice!