Implantation & the Luteal Phase
Week by Week Timeline >> Implantation & the Luteal Phase
Luteal Phase, Implantation, and When to Test for Pregnancy
> TTC Weeks 1 and 2: From Menstruation
> TTC Week 3: From
Ovulation to Conception
4: Implantation and the Luteal Phase
> Pregnancy Week 1: Early
Pregnancy Symptoms & Fetal Development
> Pregnancy Week 2: What
to Expect During Your First Trimester
1 of our discussion, we looked at how your body prepares for ovulation and
pregnancy - the build-up of the endometrium and the development of the ovarian
follicle. In Part
2, we observed ovulation and followed the egg down the fallopian tube where
fertilization/conception took place. Now we are on the fourth week of your cycle
- in the middle of the luteal phase - and things are heating up (quite literally).
Let's see why...
The luteal phase of your
menstrual cycle comprise the cycle days following ovulation. This two-week period
is called the luteal phase because of the dominant role played by the corpus
luteum, which is nothing other than the collapsed follicle from which the egg
issued forth. Now, it's the job of the corpus luteum to pump out the hormone
progesterone and "heat up" the body and womb in preparation for pregnancy.
Progesterone also helps
the endometrium thicken and become more vascular, and in this way the endometrial
lining becomes like a "soft pillow" to catch the descending blastocyst
(fertilized egg). Last and certainly not least, progesterone sends a signal
to your brain to not commence with menstruation, the shedding of the
uterine lining known as your period. As we shall see, the developing embryo
has its own hormonal signal that will tell the body "I'm here!" in
order to forestall menstruation by telling the body to keep making progesterone.
When this hormone, hCG, shows up, you can detect it with a pregnancy
test and discover that this was the lucky month!
The Body and The
Luteal Phase: With progesterone high, women may experience tender breasts
and nipples. Confoundingly, this is also an early pregnancy symptom as well.
If you are fertility charting and you know where you are during your cycle,
you can dismiss this early tenderness as a possible effect of post-ovulation
progesterone. However, if tenderness continues or intensifies when you normally
do not experience this sensitivity, you may have an early pregnancy sign.
Progesterone can also precipitate
PMS-symptoms like irritability, moodiness, etc.
After ovulation takes place,
your cervical mucus will also undergo changes. Likely, the
amount of mucus will decrease (some women experience dryness here) or the color/texture
will change from transparent-stretchy to a white or yellow shade that is a bit
more sticky and firm. Of course, women may experience different types of CM
after ovulation and throughout the first part of the luteal phase. If you suspect you may have issues relating to CM, a product called FertileCM can help to improve the quantity and quality of cervical mucus you produce.
In Part 2, we last saw the
egg undergoing certain changes following fertilization (i.e., differentiation,
becoming-blastocyst). The zona pellucida that once protected the incipient embryo
now becomes redundant and the blastocyst produces an agent to dissolve this
protective shield. At this point, the blastocyst escapes from the zona pellucida
and becomes a free-floating body within the womb.
We're now nearly a full
week after ovulation and conception. Progesterone levels are high and embryo
is ready to "hook up" with the mother-to-be. If all goes well, the
embryo will now land within the endometrium and connect to the wall of the uterus.
This process is called implantation and is formerly the first
moment of pregnancy, when the blastocyst technically becomes the embryo.
During the process of implantation, cells on the surface of the blastocyst make
contact with the endometrial lining and begin to chemically "open up"
a space within the lining where the fertilized egg may fasten. As a fold or
region in the endometrium is produced, the blastocyst (now embryo) nestles itself
within the uterine lining. This event may cause some tell-tale signs - and potentially
the very first symptom of pregnancy, implantation bleeding. Implantation
bleeding is simply defined as light spotting that may appear during the implantation
process. The color of the blood will not be red, as with your period, but typically
a pinkish or brownish shade. Not all women will experience this spotting - in
fact, most do not - so if you do not observe implantation bleeding, this does
not at all delimit the possibility of pregnancy. So now we have an embryo and,
ta-da, pregnancy has just been achieved!
When Can I Take
a Pregnancy Test?!? The question we have all been waiting for! At this
point, breast tenderness may be attributable to naturally-occuring amounts of
progesterone independent of pregnancy. Implantation spotting, while possible,
is by no means a necessary sign. So now we wait for the day we can commence
with pregnancy testing. As implantation typically occurs between six and ten
days after you ovulate - and pregnancy testing should not officially begin before
implantation - deploying pregnancy tests during the week following ovulation
is generally a simple waste of money. But before we begin with when we can test,
let's look at how pregnancy tests work in relation to what is going on with
the embryo and your body...
the embryo continues to burrow into the endometrium and its fertile matrix of
vascular-rich tissue. At this stage, the embryo casts a membrane around itself
called the chorion, which is the inner layer of the developing
placenta. The chorion's job is to establish a connection between
the life-sustaining womb and the embryo, tapping into blood vessels in the endometrium
that will nourish the fetus during your 9 months of pregnancy. Once this critical
link is made, the placenta will begin to form around the chorion and embryo,
the intermediary zone between mother and fetus where nutrients are ushered in
and waste products removed. With the nascent placenta, the bubble-like amnion
forms around embryo to shield and nourish the fetus during pregnancy, sustaining
the fetus in protective amniotic fluids that both prevent the dehydration of
fetal tissues and relieve any potential damaging pressure from within the womb.
With the development of
placental tissues, the fetus is ready to tell mom to go ahead and not have her period - in effect, to "shut down" the menstrual cycle. This
important message is, like all previous bodily communiques, conducted via hormonal
signals and triggers. In this case, the placenta issues forth an agent call
hCG, or Human Chorionic Gonadotropin, and if you have already read the description
from our product description page, then you know that this is the hormone detected
by our pregnancy tests. So, hCG is now flowing through your system and emphatically
encouraging your corpus luteum to keep pumping out the progesterone - in turn
preventing menstruation. This is why you experience your "missed period",
another fundamental pregnancy symptom. We also attribute morning sickness to
this hormone as well.
So, after this long exegesis
on hCG, we're still at a week after ovulation or so. We now understand that
the "Chorion" in Human Chorionic Gonadotropin is related to the formation
of the placenta. hCG is now flooding through your body, and the amount of hCG
increases rapidly during the first weeks of pregnancy, doubling nearly daily.
At seven to ten days past ovulation, you can begin testing for pregnancy with
higher sensitivity pregnancy tests. Early detection pregnancy tests are excellent,
though if you do receive a negative result this early, this should not be interpreted
conclusively that pregnancy was not achieved. hCG can increase at different
speeds, so we do urge you to test again using first morning urine samples. If
you only have a few of our tests, we suggest taking the first one at ten days
past ovulation and the second test a week later. What's nice about our very
affordable test strips is that you can test practically daily!
We'll pick an arbitrary
day - how about 10 DPO , or ten days past ovulation? You just awoke
and tested with a first morning urine. The control line materializes almost
immediately and slowly but surely you see a test line hovering at the threshold
of perception. Three minutes pass and you see your first test color band, albeit
somewhat faint. At five minutes, the complete reaction time of the test, it's
clearly there - a faint but distinct color band in the test region of the strip!
As hCG develops in your body, this test line should deepen and become bolder
over the following days with consecutive follow up tests.
Next... Pregnancy Week 1:
Symptoms & Fetal Development
> Pregnancy Week 2: What
to Expect During Your First Trimester
Week by Week Timeline