Dealing with the more common latter option first, having a period is dictated by bleeding in the uterus. This occurs when its lining, the endometrium, breaks down due to failure of implantation due to no embryos being planted. Having regular menstrual cycles is a sign that important parts of your body are working normally.
See a doctor if you have not started having periods after three years of secondary characteristics of sexual growth such as breast and hair growth; the period is referred to as an example of a primary characteristic.
As a girl matures and enters puberty, the pituitary gland releases hormones that stimulate the ovaries to produce other hormones known as oestrogen and progesterone. These hormones have many effects on a girl's body, including physical maturation, growth, and emotions. About once a month, ovulation occurs; a tiny egg leaves one of the ovaries and travels down one of the fallopian tubes toward the uterus.
In the days before ovulation, the hormone oestrogen stimulates the uterus to build up its lining with extra blood and tissue, making the walls of the uterus thick and cushioned. This happens to prepare the uterus for pregnancy: If the egg is fertilized by a sperm cell, it travels to the uterus and attaches to the cushiony wall of the uterus, where it slowly develops into a baby. This is how pregnancy is known. Pregnancy has occurred when a period is missed and the lining has not broken down; always check with an over the counter kit that an egg has fertilized. If the egg isn't fertilized however, it doesn't attach to the wall of the uterus. The blood, tissue, and unfertilized egg leave the uterus, going through the vagina on the way out of the body. Menstrual cramps often become less uncomfortable and sometimes even disappear completely as a girl gets older.
See a doctor if you have not started having periods after three years of secondary characteristics of sexual growth such as breast and hair growth; the period is referred to as an example of a primary characteristic.
As a girl matures and enters puberty, the pituitary gland releases hormones that stimulate the ovaries to produce other hormones known as oestrogen and progesterone. These hormones have many effects on a girl's body, including physical maturation, growth, and emotions. About once a month, ovulation occurs; a tiny egg leaves one of the ovaries and travels down one of the fallopian tubes toward the uterus.
In the days before ovulation, the hormone oestrogen stimulates the uterus to build up its lining with extra blood and tissue, making the walls of the uterus thick and cushioned. This happens to prepare the uterus for pregnancy: If the egg is fertilized by a sperm cell, it travels to the uterus and attaches to the cushiony wall of the uterus, where it slowly develops into a baby. This is how pregnancy is known. Pregnancy has occurred when a period is missed and the lining has not broken down; always check with an over the counter kit that an egg has fertilized. If the egg isn't fertilized however, it doesn't attach to the wall of the uterus. The blood, tissue, and unfertilized egg leave the uterus, going through the vagina on the way out of the body. Menstrual cramps often become less uncomfortable and sometimes even disappear completely as a girl gets older.
