What is ovulation?
Ovulation occurs when a mature
egg is released from the ovary, enters the fallopian tube, and becomes
available for fertilization. About every month, an egg matures in one of your
ovaries. When she reaches maturity, the egg is released from the ovary, where
it travels down the fallopian tube on its way to the waiting sperm and uterus.
The lining of the uterus thickens to prepare for a fertilized egg. If
conception does not occur, the lining of the uterus is shed along with the
blood. The prolapse of an unfertilized egg and the wall of the uterus is the
time of menstruation.
Basic facts:
- An egg lives 12-24 hours after leaving the ovary
- Normally only one egg is released each time of ovulation
- Ovulation can be affected by stress, illness or disruption of normal
- Some women may experience some light blood or spotting during ovulation
- Implantation of a fertilized egg normally takes place 6-12 days after ovulation
- Each woman is born with millions of immature eggs that are awaiting ovulation to begin
- A menstrual period can occur even if ovulation has not occurred
- Ovulation can occur even if a menstrual period has not occurred
- Some women experience pain/aching near ovaries during ovulation called ‘middle pain’
- If an egg is not fertilized, it disintegrates and is absorbed into the uterine lining
How to track your cycle
A woman's monthly cycle is
measured from the first day of her period to the first day of her next period.
On average, a woman's cycle is usually 28 to 32 days, but for some women,
cycles can be much shorter or much longer. Ovulation can be calculated starting
from the first day of the last period or counting 12-16 days from the next
expected period. For most women, ovulation occurs somewhere between days 11 and
21 of the cycle, starting on the first day of the last period. This is what
many refer to as the "fertile period" of a woman's cycle because
intercourse during this time increases the chances of pregnancy. Ovulation can
occur at different times during the cycle and may occur on different days of
each month. Keeping track of your cycle is important, and thankfully, there are
a number of free fertility charting tools available to help women identify peak
fertility days.
The ovulation cycle is divided into two parts
The first part of the cycle is
called the follicular phase. This phase begins on the first day of the last
menstrual period and continues until ovulation.
This first half of the cycle
can vary greatly from woman to woman, ranging from 7 to 40 days.
The second half of the cycle
is called the luteal phase and lasts from the day of ovulation until the start
of the next period. The luteal phase has a more precise time scale and is
usually 12 to 16 days from the day of ovulation.
Ultimately, this means that
the day of ovulation will determine the length of your cycle. It also means
that external factors such as stress, illness, and disruption to your normal
daily routine can disrupt your cycle, which then causes your menstrual cycle to
change. Thus, the old idea that stress can affect the menstrual cycle is only
partly true. Stress can affect your ovulation, which ultimately determines when
your period comes, but stress during your expected period won't delay it - it's
already determined when it comes 12-16 days early!
Fertility awareness is one way
to track when you ovulate, including noticing changes in cervical mucus and
using a basal thermometer. Cervical fluid turns into a moist, slippery
substance similar to "egg white" just before ovulation and before it
ends. The basal thermometer helps track the rise in body temperature, which
signals that ovulation has just occurred.
Another way to track your
cycle is to use ovulation kits and fertility monitors. They are affordable and
can be purchased online. Tracking ovulation can help a woman better understand
when pregnancy can and cannot occur during her menstrual cycle. Once ovulation
has occurred, there is nothing you can do to increase your chances of
pregnancy. Your next step is to start watching for early pregnancy symptoms.
When the menstrual cycle
begins, estrogen levels are low. Your hypothalamus (which is responsible for
maintaining hormone levels) sends a message to the pituitary gland, which then
sends out FSH. This follicle-stimulating hormone causes some of your follicles
to turn into mature eggs. One of them will develop into a dominant follicle,
from which a mature egg will be released, and the rest will disintegrate.
As the follicles mature, they
release another hormone, estrogen. High levels of estrogen tell the
hypothalamus and pituitary gland that the egg has matured. Luteinizing hormone
is then released, called the luteinizing hormone surge. The surge in
luteinizing hormone causes the egg to break through the ovarian wall within 24
to 36 hours and begin its journey down the fallopian tube for fertilization.
Ovulation predictor kits work by detecting this luteinizing hormone surge. The
follicle from which the egg is released is called the corpus luteum and
secretes progesterone, which helps thicken and prepare the uterine lining for
implantation. The corpus luteum produces progesterone for about 12-16 days (the
luteal phase of your cycle).
If the egg is fertilized, the
corpus luteum will continue to produce progesterone for the developing
pregnancy until the placenta takes over. You can start looking for signs of
pregnancy as early as a week after fertilization. You can also start pregnancy
testing as early as 7-10 days after your ovulation date with an early detection
pregnancy test.
If fertilization does not
occur, the egg dissolves after 24 hours. At this point, hormone levels will
drop and the lining of the uterus will begin to slough off about 12 to 16 days
after ovulation. This is your period and it brings us back to the first day of
your cycle. Then the journey starts again.
The timing of ovulation is one of the most important things a woman needs to know about her body as it is the determining factor in getting pregnant and preventing pregnancy.