One of the first signs of puberty as a girl is when your breasts start to develop and it's a whole long process that goes a little bit like this. First you get something called a breast bud which is like a nickel sized lump underneath your nipples. And sometimes they're sore and tender. They may be so sore that it's hard to sleep on your stomach. You should just sleep on your back. It's totally normal. The next part of development is that the areola, which is that dark circle that's around your nipples, starts to get wide and together with the nipple it forms its own mound. This is normal too. In time your breasts will take on the shape and contour that it will when you're a grown up and it will start to become more round. Don't freak out if one of your breasts is slightly larger than the other one or is growing faster than the other one. This is completely normal.
In fact, one out of two women have one breast slightly larger than the other and it's nothing to worry about. During the time that your breasts develop a lot of girls ask questions and one of the questions I get a lot is, "Are my breasts going to get big right away?" The answer to that is no. They're not going to get big right away. This is a long process that happens over the course of several years so don't flip out if you're growing gradually. That is totally normal. Another question that I get is, "Are my breasts too small or my breasts too large?"
This is an upsetting question because I think that the media, in my opinion, places way too much emphasis on what girls' breasts look like which may make you feel a little insecure or uncomfortable or self-conscious. Don't believe the hype. Your body is going to get to the size that it's going to get to because of many different reasons and mostly because of your genes. The size of breasts that run in your family will eventually be the size of breasts that you have and that's totally normal. So don't pay attention to outside sources. You will get to your normal size in no time.
Another question that I get is about training bras. Girls want to know when to wear a training bra. At first you really don't need to wear a training bra but because some girls breasts are sore and tender you may want to wear one just to protect yourself from outside clothing.
Some girls find it nice to wear a soft, 100 percent cotton undershirt, or even a sports bra might help with this. And just remember, when it comes to breast size there's a large range of normal.
So ignore the media hype. If you're looking in magazines or television shows your breasts are not supposed to be one set size. Everybody is different so just relax and enjoy the ride.