Menstrual cycle/ovulation

A woman's ability to become pregnant is cyclical. The process that prepares a woman's body for pregnancy each month, called the menstrual cycle, is regulated by the hormones estrogen and progesterone. Most girls begin to menstruate between ages 10 and 16, often around age 12.


The menstrual cycle
Menstruation marks the beginning of the reproductive years. The menstrual cycle has three phases: follicular, ovulatory and luteal.
The follicular phase begins with the first day of your cycle -- the first day of your period. For most women, bleeding lasts three to five days. Estrogen and progesterone levels begin to rise, causing a follicle to develop within the ovary and the uterine lining to thicken. The follicle holds the egg that will be released when it reaches maturity, and the uterine lining thickens in preparation for a fertilized egg. The follicular phase usually lasts about 14 days. The duration may vary for each woman, however, or even change slightly from month to month.

Ovulation occurs when the follicle releases the mature egg, usually on about day 14 to 15 of the cycle. The egg is able to be fertilized for about a day after it's released from the follicle. Sperm, on the other hand, can survive for about 48 hours inside the female reproductive tract. You have the best chance of conceiving if you have sex daily around the time you ovulate. During the rest of the cycle, the chance of pregnancy drops. If fertilized, the egg implants itself in the uterus about a week after fertilization. Because illness, stress, exercise and even the weather can cause variations in ovulation, the exact day of ovulation varies considerably.

If the mature egg is not fertilized, it will break down and the cervical mucus may become thick and sticky. This phase, known as the luteal phase, begins on about day 15 to 16 and lasts about 14 days. Premenstrual symptoms often appear near the end of this phase -- just before your next period begins.


Considerations
Many women get their periods every 28 days. Some have a menstrual cycle every 25 days, however, and others go as long as 32 days between cycles. Once menstruation begins, it's important to remember that pregnancy is possible with each episode of unprotected sex.

Signs/symptoms
The hormonal changes taking place in your body may cause a variety of symptoms during your menstrual cycle. The symptoms may be mild or severe.
During the follicular phase, you'll have menstrual bleeding. You may also notice abdominal pain or cramping and low back pain as the uterus contracts to expel the blood.

During ovulation, you may notice an increase in clear vaginal secretions resembling an egg white, abdominal pain, light vaginal spotting and a rise in basal body temperature. To help determine if you're ovulating, record your basal body temperature every morning before getting out of bed, eating or drinking. A rise of a half to one degree may indicate that you've ovulated. Special calendars are available to chart basal body temperature. As another option, buy an ovulation monitoring kit and follow the directions carefully.

During the luteal phase, you may notice premenstrual symptoms such as:

fluid retention and decreased urination
breast tenderness
depression
anxiety, irritability and nervousness
poor concentration and impaired judgment
bloating, constipation or diarrhea
hot flashes
dizziness or fainting
changes in sex drive
headaches
acne

Treatment
To relieve menstrual discomforts, your doctor may recommend the following self-care measures:
Limit your intake of salt, sugar and caffeine, especially the week before your period.
Get plenty of rest.
Exercise moderately.
Take a warm bath or place a hot water bottle or heating pad over "crampy" areas.
Take an over-the-counter pain medication, such as acetaminophen or ibuprofen.
In some cases, birth control pills can ease symptoms as well.


Complications
Call your doctor if your period lasts more than 10 days or you begin to bleed heavily (you saturate a pad every hour or a tampon every 15 minutes). It's also a good idea to consult your doctor if self-care measures don't relieve severe menstrual symptoms.