Getting Pregnant (Baby Making 101)

How Does The Menstrual Cycle Work?

Understanding the menstrual cycle is important at any time of a woman's life, but it is vital when you're trying to get pregnant. It can help you understand how to time sex when you are most fertile, as well as getting to know your body better. Listed below is a brief overview of each process involved:

At birth

Each female baby is born with around 450,000 egg cells stored in their ovaries for a lifetime. Each egg lies in follicles in small pockets. Upon puberty, between the ages of 10 to 14, different hormones ripen the follicles so that an ovum (egg cell) is released.


A hormone is a chemical receiver produced by the body. This substance regulates both the menstrual cycle and body temperature. It also triggers ovulation.

Monthly period

Some blood vessels in the mucus membranes open up for a time at the end of the cycle. The egg cell, together with the uppermost mucous layer and an egg is shed through the vagina. This is called menstruation, which basically is the body getting rid of tissue it doesn't need. It is commonly known as a period. A period will last 3 - 5 days. As long as hormonal contraceptives are not used and the woman is not pregnant, the period is a sign that one menstrual cycle has finished and the next has started.

During a period the muscles of the uterus tighten and relax in a rhythm in order to shed the mucus membrane and blood. This process allows the tissue to become detached from the wall of the uterus, leaving the body through the vagina. During a monthly cycle only 4 - 12 teaspoons of blood is shed. When on a pad or tampon this amount of menstrual fluid can look considerably more.

Normal menstrual cycle

An average cycle lasts 28 days - counting from the first day of one period to the day before the next. Some cycles are shorter, possibly lasting for only 23 days, and some women have much longer cycles, lasting up to 35 days. If bleeding occurs between periods or after sex it would be advisable to see a doctor.

Ovulation / Pregnancy

A woman can get pregnant around the time a mature egg leaves the ovary. The cell travels down the ovarian tube into the uterus (also better known as the fallopian tube). The journey from ovary to uterus takes about 5 days.

Ovulation takes place the moment the cell leaves the ovary. Once a woman has her first monthly menstruation, ovulation takes place once a month. The mucous membrane lines the uterus in preparation that an egg may fertilize and settle in the uterus. At this implantation stage the fertilized egg is made up of about 150 cells. If a woman gets pregnant the mucous membrane supplies nutrients to the embryo. As levels of progesterone rise, breasts may feel tender and tingly. The pituitary gland stops producing FSH (follicle stimulating hormones) so that no more eggs mature in the ovaries.

If the egg cell is not fertilised or does not successfully implant, it starts to disintegrate and the egg dies. The oestrogen and progesterone levels drop, causing a chemical change in the blood supply to the uterus and breaking up the lining, simulating the uterus to contract. The period starts and the lining of the uterus is shed along with the unfertilised egg. This is the beginning of a new menstrual cycle.


Menopause will take place generally around 50 years of age; however, this can differ from one person to another. This is the medical term for the end of the menstrual cycle and the last period. Until the age of 40 years, the amount of follicles in the ovaries can drop considerably. After this time the number drops quickly until no follicles ripen at all. This is a deciding factor that the menopause is beginning.

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This internet site provides information of a general nature and is designed for educational purposes only. If you have any concerns about your own health or the health of your child, you should always consult a doctor or other healthcare professional.