Pregnancy by week

Your pregnancy: 3 weeks

Things are in their very, very early stages, but you might still be curious about your pregnancy and embryo development at 3 weeks pregnant and what kinds of symptoms to expect.

By Today's Parent

Your pregnancy: 3 weeks

Photo: iStockPhoto

Take a deep breath

If you’re reading this, your world is probably feeling a little off-kilter right now. “I’m pregnant? Really?!” The majority of women don’t know they’re pregnant until several weeks after this point, but perhaps you’ve been on this particular roller coaster before, you’re in the care of a fertility clinic or you’ve had a sneaking suspicion that you should take an early-result pregnancy test. Three weeks pregnant? It was only a week ago that you ovulated and egg met sperm, so things are in their very, very early stages.

Learn about the stages of your pregnancy with our detailed week-by-week guide, detailing how your body is changing, plus the growth and development of your baby.

Worried girl after looking a pregnancy test milanvirijevic / Getty Images

What’s going on in there: Embryo development at 3 weeks pregnant

Around three weeks pregnant, the fertilized egg is taking a five- to six-day journey through one of your fallopian tubes. Along the way, it’s dividing and redividing into identical cells and smaller than the period at the end of this sentence. Its ultimate destination? Your uterus, which is starting to develop a thicker lining as a cozy home for the next nine months. This fertilized egg is called a “morula” at three or four days after fertilization because it is made of 16 cells and looks like a berry (“morula” is “mulberry” in Latin) and a “blastocyst” at five or six days after fertilization. And the follicle in your ovary where your egg started out? The empty space is filled with a mass of yellowish cells called the corpus luteum, which produces progesterone and estrogen to suppress menstruation and produce other nutrients that are needed to nourish the pregnancy.

The blastocyst is ultimately made up of several hundred cells, and it implants, or burrows, into the lining of your uterus. Once this happens, microscopic tunnels connect the developing embryo to the blood vessels in the uterus, delivering oxygen and nutrients to the embryo and removing waste. The cells in the middle will become the embryo, and the exterior cells will develop into the placenta (the placenta will then take over the job of oxygen, nutrient and waste transfer). These future placental cells are also creating human chorionic gonadotropin (hCG), also known as the pregnancy hormone. This hormone tells your body to stop releasing eggs and keep producing progesterone, which keeps the uterine lining in the uterus (rather than being shed during a period). Amniotic fluid is beginning to fill the amniotic sac. It’s pretty mind-blowing to think of everything that’s going on in there at such a microscopic level!

RELATED: Your pregnancy: The first trimester

Three weeks pregnant symptoms

At only three weeks pregnant, you may have no symptoms at all, and that’s totally fine. It’s also totally fine to have some early pregnancy symptoms. If you have higher levels of hCG, you may start to feel queasy. Other early pregnancy signs (yes, even as early as three weeks pregnant!) include tender boobs prepping for breastmilk already, heartburn, bloating and gassiness. The tummy issues may be thanks to progesterone, which relaxes muscles throughout the body and can slow down digestion. Extra estrogen may leave you with a heightened sense of smell. Higher hormone levels can lead to a slight feeling of breathlessness, which is also affected by your adjustment to sharing blood and oxygen with your little embryo.

woman touching her forehead and feelin dizzy Eleganza / Getty Images

Light cramping is ok

You may also have some light cramping and spotting, known as implantation bleeding. Implantation bleeding occurs in about one-third of pregnancies and happens about five to 12 days after conception. Why? As the embryo attaches to the lining of the uterus, tiny blood vessels break and you end up with a small amount of blood on the toilet paper or your undies. It is much lighter and shorter than a period and can be reddish, pinkish or brownish.

RELATED: How to respond to ridiculous comments people make when you're pregnant

young woman feeling cramps LaylaBird/ Getty Images

What’s on your mind this week

If you used a home pregnancy test, you may be wondering just how accurate it is. For example, what does it mean if the line is faint? This test measures the amount of hCG in your urine, so if it’s done later in the day, it may be diluted and cause a lighter line (in other words, pee on the stick first thing in the morning). However, since this is still such an early stage of pregnancy, the test may be inconclusive or inaccurate—that’s because the level of hCG that indicates pregnancy can usually only be detected 12 to 14 days after conception, and your levels may not be there yet. The chances of a false negative (a test that says you’re not pregnant but you actually are) are higher in those early days. You can repeat the test in a few days or, if you miss your period, talk to your healthcare provider about a blood test.

Woman waiting for pregnancy test result ilona titova / Getty Images

Just for kicks

How are you going to tell your partner that you’re pregnant? If you’re a planner, there are some fun ways to share the big news (or maybe you could just blurt it out—your call!). You can also start thinking about creative and hilarious baby announcement ideas to spread the news with others down the road.

RELATED: 5 things I didn't know when I first got pregnant

Young couple sitting at table in a cafe talking with serious faces. Carlos Pintau / Getty Images

Baby names

It’s really early to be thinking about baby names at this stage in the game, but if you’ve been fantasizing about this day for a long time, you might want to take a little peek at these baby name trends. It might just take nine months to agree on one!

woman with smartphone on a sofa Delmaine Donson / Getty Images

Pregnancy to-do list: Week 3

You really don’t have to do anything but process the news this week. If you live in an area where midwives and OB/GYNs are in demand, you might want to make an initial phone call to find out about appointments and availability. Want to get a head start on your pregnancy and birth reading? Here are some of the pregnancy books we like. Remember, you’re just at the very beginning of an amazing journey.

RELATED: What to expect if you get pregnant while you're still breastfeeding

Read more: 14 best pregnancy books that are worth buying 88 things nobody tells you about being pregnant Up next: 4 weeks pregnant

Your pregnancy: 3 weeks
This article was originally published on Jan 23, 2020

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