As your breasts start to develop during puberty, your nipples will go through some changes as well. As you start to get breasts, you may notice that the areola, the dark skin around the nipple, starts to grow.
As your whole breast gets larger, both your nipple and your areola will get darker in color and also start to "stick out" a little. That is, they’ll become their own little mound on top of your breast.
Some girl’s nipples stick out when they’re cold or excited; other girls’ don’t. If yours do, and this bothers you, you can choose to wear a bra with a little bit of padding so your nipples aren’t as visible.
Some girls are born with what are called inverted or retracted nipples. Inverted nipples are like innie belly buttons: They stick inward instead of outward. Inverted nipples are totally normal.
It’s not unusual for puberty nipples to give out a little bit of milky fluid, so don’t freak out if this happens to you.