When you first get your period, girl's should become use to using pads, not tampons. Tampons are alittle to advanced for beginners. Around this time, the ovaries begin to make mature eggs. When a girl has mature eggs, the girl is then able to have a baby. All those examples of what can happen to a girl when they go through puberty are all caused from estrogen.
Most young women have a breast which tends to grow slower than the other breast.
This is normal because they will soon begin to grow equal with in a matter of time. No need to freak out. Boy's When guys go through puberty, their hormones start to change. Hormones are released by the pituitary gland. The pituitary gland stimulates the testes to make the hormone testerone.