So you're pretty sure you've ovulated, and you did your best to
get pregnant - what now?
The waiting time after ovulation until you are able to either
take a pregnancy test or experience menstruation can be agonising,
particularly if you have been trying to get pregnant for a
In the "average" 28 day cycle, menstruation occurs on Day 1 and
ovulation occurs after this at around Day 14.
Many women get confused by the "Day 14" terminology and assume
that ovulation occurs fourteen days after menstruation has ended,
when (assuming an 'average' 5 days of menstruation) it is more
likely to be around nine days after menstruation has finished.
It is usually around fourteen days after ovulation, before
menstruation starts again - however very few women have an
The time after ovulation is known as the "luteal phase" and is
the longest-lasting phase of the menstrual cycle.
It is only possible to get pregnant for a short period of time
After ovulation - when the egg is released from the follicle -
there is a period of between 12 and 48 hours when the egg is
available to be fertilised by a mature sperm.
Sperm can last for up to five days inside a woman's body,
sustained by the cervical mucus - so often, just after ovulation,
sperm already waiting in the fallopian tubes will fertilise the egg
after it has just been released.
Healthy, active sperm take around six hours after ejaculation to
swim through the cervix and the uterus into the fallopian tube to
meet a waiting egg, so for one to two days after ovulation, it is
still possible to fall pregnant.
In any one menstrual cycle, there will be just one fertile
period. As levels of FSH (follicular
stimulating hormone) rise, a number of follicles develop in your
ovaries, but usually just one is released.
Because ovulation is triggered by a particular combination of
hormones that rises and falls over the normal menstrual cycle, eggs
can only be released from the ovaries during the 24-hour period
when the ovulation-promoting hormones are at their peak.
A pregnancy with fraternal twins results from two eggs being
released from two different follicles, within the same 24-hour
Between one and three percent of all births are fraternal twins.
However, advances in ultrasound technology have led to research
into the "vanishing twin syndrome."
It is now thought that up to one in eight pregnancies may
involve the very early fertilisation of more than one egg, but less
than half of the second embryos will survive for more than a few
weeks after ovulation. If the embryo does not survive, it is
reabsorbed by the body.
After ovulation, hormone levels decline and you must go through
a feedback cycle which triggers menstruation before you ovulate
For the next eight days or so after ovulation, the same events
occur in your body whether the egg has been fertilised or not.
The follicle which released the egg grows larger and turns into
a gland-like structure called the "corpus luteum." After this, it
then starts to produce the hormone progesterone, which causes the
lining of the uterus (the endometrium) to grow thick and become
covered with mucous that is produced by glands within the
After ovulation, if you are not pregnant, within 48 hours, the
egg moves along the fallopian tubes, disintegrates and is absorbed
back into the body.
The corpus luteum survives and continues to produce progesterone
for around 12 to 14 days. After this, it dies (unless it receives
the hCG hormone released from an embryo).
The level of progesterone in the body drops and the endometrium
responds by shutting off its arteries, preventing blood from
flowing to and from the surface of the uterine lining.
The blood that is already in the lining then pools lower in the
uterus and the mucous-covered uterine lining, deprived of oxygen,
dies back, the blood and lining seep into the vagina, so
menstruation occurs and the cycle begins again.
After ovulation and until menstruation, your basal body
temperature remains about 0.5 degrees Celsius higher. Your cervical
mucus becomes less slippery and more sticky or creamy in
The moment that one of the millions of sperm enters the outer
surface of the egg, the egg's coating changes so no other sperm can
enter, the sperm and egg combine and form a "zygote."
After this, the zygote takes around five days to travel down the
fallopian tube, with cells dividing and eventually forming a
Around eight to ten days after fertilisation, the blastocyst
implants into the wall of the uterus.
Before implantation, there's not a lot of change going on in
your body, which behaves just as it would if you weren't
But after ovulation and then implantation, the fun begins.
Sometimes there is a slight spotting or bleeding just after
implantation - which some women mistake for a period.
But when the blastocyst attaches to the endometrium, becoming an
embryo, various hormones are released which thicken the endometrium
and seal the cervix with a plug of mucous.
The embryo and placenta develop separately. After implantation,
the placenta produces the hormone human chorionic gonadotropin
(hCG). Within a few days, the level of hCG is able to be detected
in urine, using a pregnancy test.
By Fran Molloy, journalist and mum of four