Menstruation and Ovulation: A Step-by-Step Guide

Menstruation and ovulation are natural processes for every woman in her lifetime, but the inner workings of the female body can seem mysterious, especially when you first hit puberty. You experience a number of changes, including monthly bleeding that may be accompanied by cramps and a score of other side effects.

The process itself, though, is not nearly as mysterious as it once was, and although only an OB/GYN can help with many of the specific symptoms, it's often useful from a mental perspective to understand exactly what is happening inside your body.

Release of Estrogen and Ovum Growth

For every menstrual cycle throughout your life, the day you begin bleeding each month is considered day one.

On day one, your body begins to produce more estrogen, which is the female hormone responsible for the fact that women are generally physically smaller than men and have less body hair — among other details. Estrogen also makes it possible for you to conceive a child.

It does this by causing the walls of your uterus to thicken. These thicker uterine walls enable a fertilized egg to be implanted in the womb.

As your uterine walls become thicker, one of the eggs in your ovaries begins to mature and prepare for release. You were born with these eggs, so the menstrual cycle only marks the beginning of the period in your life when they will mature. You only have a finite number, and they are released monthly throughout your fertile years.


The specific menstrual cycle differs from woman to woman, which is why it is so important to track and document your period. 14 days is the average, but it can be shorter or longer depending on genetics and other factors.

Mid-cycle, though, is when the egg that began maturing on day one leaves your ovaries and moves through the fallopian tubes into the uterus. The formal medical term for this process is ovulation.

You will generally be fertile — able to conceive a child — for three days before ovulation. If sperm enters your uterus during this time, it can attach to and fertilize the egg. The fertilized egg will, in most cases, attach itself to the thickened wall of the uterus and begin growing into a fetus in a process called implantation.


If implantation occurs and there are no complications, you will be pregnant by the time you reach around day 28 of your cycle. In fact, the absence of a period is how many women realize that they are pregnant in the first place.

If, however, there was no fertilized ovum implanted in your uterus, you will begin to shed the thicker uterine lining so that your body may start the process anew. During this time, the body produces less estrogen and progesterone, and the previously thickened uterine lining swells and begins to break down naturally.

The breaking down of the uterine lining creates prostaglandins. These molecular compounds create muscle contractions in the uterus.

The contractions are responsible for what many women feel as menstrual cramps, but they are necessary to remove the remaining additional tissue from the wall of your uterus so that the body can start the menstruation and ovulation process over. The shedding of the uterine wall takes about five days — a number that fluctuates from woman to woman like every other aspect of the menstrual cycle —and creates the bleeding known as menstruation, which is commonly called "your period."

Aside from cramping from muscle spasms, women may experience a number of other side effects during menstruation, including bloating from water retention, headaches and excessive tiredness. These are all related to the slowed production of estrogen and progesterone during this time.

What Constitutes a "Normal" Period?

The numbers here are all averages, but again, each woman's body will differ slightly in both fertility cycle and the length of the menstrual period. For this reason, most medical professionals recommend that a woman carefully document her menstruation from the time it begins during puberty so that any changes in the cycle are noticed as quickly as possible.

If you begin to notice changes in your cycle, find yourself bleeding for seven days or more per month, or experience severe menstrual cramping and other symptoms, be sure to contact an experienced, board-certified obstetrician at Gainesville's All About Women as soon as possible to obtain tests and possible treatment.