Three things are necessary to become pregnant. The egg, the sperm
and cervical fluid for the sperm to travel in.
The individual eggs are housed in follicles. A
hormone called FSH (Follicle Stimulating Hormone) enables your body to bring 15
to 20 eggs to maturity in each ovary. The follicles that hold the eggs start to grow
and produce estrogen which is a necessary hormone for ovulation to occur.
Ovulation is the process of an egg being released from the most
dominant follicle. Ovulation takes place approximately two weeks from
the first day of the monthly cycle but can vary from woman to woman and even
from month to month since the body waits until it has reached a
sufficient level of estrogen. Once this level is reached the body will
release a surge of LH (Luteinizing Hormone), which is the hormone that causes the
egg to actually burst through the ovarian wall. The remaining eggs will eventually
ripen and disintegrate. The dominant egg then ventures into the pelvic cavity.
If the egg is not picked up and drawn into the
fallopian tubes then no pregnancy will occur. The follicle that held the egg
will collapse on itself and become a corpus luteum. The presence of the corpus
luteum is what constitutes the luteal phase of a women's cycle.
The corpus luteum remains
behind after the release of the egg on the interior ovarian wall and will start
to produce yet another hormone called progesterone. Progesterone prevents the other eggs from being released during that cycle,
strengthens and thickens the uterine lining (endometrium) and causes all of the
fertility indicators (waking body temps, cervical fluid and
position) to change.
If pregnancy does not take place during the cycle, the uterine lining
or endometrium is shed,
which causes menstruation to occur. The first day of menstruation is the first day of a monthly cycle
which begins the whole process again.
Usually when the egg enters the pelvic area it is swept into
one of the fallopian tubes by fingerlike projections called fimbria. Sperm
travels up the fallopian tube with the help of cervical fluid. Fertilization occurs in
the outer portion of the tube when the sperm penetrates the egg. The now
fertilized egg will travel down to the uterus which takes approximately 6 to 8
days and will then burrow into the uterine lining.
The burrowed egg immediately starts to release
HCG (Human Chorionic Gonadotropin) which is
also known as the pregnancy hormone and is what is
detected to give a positive pregnancy test result. HCG
causes the
corpus luteum to survive longer than the normal 12 to 16 days. The lengthened
life of the corpus luteum enables the continued release of progesterone, which is
responsible for sustaining the uterine lining and supplying nutrients and oxygen to
the fetus until the placenta can take over and continue to provide for the growing
fetus.
