menstrual cycle

Understanding Your Menstrual Cycle

"Understanding Your Menstrual Cycle is critical to charting fertility, predicting ovulation, and increasing your chances of conception."

Understanding Your Menstrual Cycle

The menstrual cycle refers to the cyclical development and then shedding of the endometrium, the lining of the uterus. Understanding your menstrual cycle is central to fertility charting, predicting ovulation, and increasing your chances of becoming pregnant.

A woman's fertile period during her menstrual cycle, on average, lasts about seven or eight days: seven days before ovulation (the release of the egg) and the day of ovulation. After this, chances of conception decrease quickly, as the egg has a life-span of only 24 hours.

Given this somewhat narrow window of opportunity for conception, understanding the menstrual cycle can help increase a woman's chances of becoming pregnant.

The Menstrual Cycle and Ovulation Prediction

The monthly menstrual cycle consists of two parts or phases - with ovulation as the midpoint between the first and second phase. The first half is pre-ovulation (or the follicular phase) and the second half is post-ovulation (the luteal phase).

The follicular phase refers to the maturation and release of the egg (ovum) from the ovary. Though the length and regularity of a menstrual cycle may differ each month, the average length of cycle is about 28 days. Please note that healthy cycles can run from anywhere between 21-36 days. Below you will find a description of a typical menstrual cycle based on a 28 day length.

Day One of your cycle is the first day of menstrual bleeding. Bleeding, or "menstrual flow", typically lasts three to five days or so. By the 7th day of the menstrual cycle, eggs (or ova) in the ovaries start to mature due to hormonal changes - the increase of follicle stimulating hormone and, in turn, estrogen.

Between day 7 and 11, the lining of the uterus (the endometrium) begins to thicken and one may observe changes in the presence and texture of cervical mucous, or CM. After the day 11, luteinizing hormone, or LH, causes the ovum that is most ripe to be released. This is ovulation, the release of the egg from the ovary. The egg then drifts down the fallopian tube. If your menstrual cycle is 28 days long, ovulation will likely take place around day 14, the very midpoint of your monthly cycle.

Ovulation marks the end of the follicular phase. Following ovulation comes the second half of the cycle, or the the luteal phase, which is characterized by a marked rise in body temperature. As noted above, once ovulation takes place, the ovum travels down the fallopian tube to the womb. The uterine lining has, over the past several days, thickened to 'welcome' a fertilized egg for pregnancy. If the ovum is fertilized by a sperm (conception), then " implantation" should take place in the uterus. Pregnancy officially takes place if the fertilized egg, now call the embryo, implants in the wall of the uterus. Without fertilization, the unfertilized egg will simply disintegrate and levels of certain hormones will drop, thus facilitating the endometrium to break down and shed. This shedding process is known as menstruation, or a woman's "period".

The first half of the monthly cycle, from menstruation to ovulation, may vary from 14 to 20 days in length. The length of the pre-ovulation phase is often different from one woman to another - but it can also differ from month to month for an individual. It is during first part of the cycle that fertilization can occur. Of course, regular menstrual patterns can be altered by illness, insomnia, stress, physical exertion, and physical and emotional changes.

The luteal phase, or post-ovulation (from ovulation to menstruation), is generally the same length for most women - averaging about 14 days. As a rule, the egg is released 10 to 16 days before menstruation, or the start of the next menstrual cycle.