3 Weeks Pregnant: Symptoms, Baby Size, Body Changes & more

3 Weeks Pregnant: What to Expect

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Dr. Sabiha Anjum (Gynecologist/Obstetrician)
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Once the pregnancy is confirmed, the expectant parents are all excited to know about their baby’s growth and development. The pregnancy term may seem like a long journey ahead, but your baby is developing slightly every week, and it is only fair that you should know everything about it. Find out about the exciting foetal development in the 3rd week of pregnancy and other pregnancy milestones that you achieve during the week through this article.

Video: 3 Weeks Pregnant: What to Expect

Baby’s Growth During Week 3 of Pregnancy

It’s the 3rd week of your pregnancy, and the good news is that the fetus is already under development. During this week, your baby is just a tiny ball with 100’s of cells that are multiplying rapidly. The part of the tiny ball or blastocyst that will develop into a placenta starts producing pregnancy hormone (HCG) in the 3rd week of pregnancy. This hormone stops the further production of eggs and triggers an increase in the production of estrogen and progesterone. These hormones ensure that your ovary doesn’t shed the uterine lining. Your little blastocyst is safe and sound in your uterine lining during the 3rd week and receives oxygen and nutrients through the tunnels that connect the little ball of cells to the blood vessels in the uterine wall.

Baby’s Size During Week 3 of Pregnancy

This week is crucial because, during this week, the fertilised egg safely implants itself in the uterine lining and starts developing with the help of oxygen and nutrients that it receives through the blood vessels of the uterine lining. While the development itself is interesting, the size of the baby is negligible. In technical terms, the baby’s length is 0.0 in the weight is 0.0 gm.

Your body will also go through some changes as your pregnancy progresses. Let’s take a look at some common changes and symptoms a woman’s body will go through at week 3 of pregnancy.

Common Body Changes

From the onset of pregnancy till the end, body changes during pregnancy in women are drastic. In the first few weeks of pregnancy, the difference that a woman feels in her body and demeanour are quite similar. In fact, each of these symptoms or changes heighten with each passing week of pregnancy. Some of the continued body changes in the 3rd week of pregnancy are soreness of breasts, elevated basal body temperature, exhaustion, and loss of appetite.

Video: 3 Weeks Pregnancy Symptoms – Know Very Early Signs of Pregnancy

Symptoms of Pregnancy at Week 3

Symptoms of pregnancy differ from woman to woman, but here are a few common symptoms that may help you to find out a week before the pregnancy test that you are pregnant.

  • Swollen or tender breasts.
  • An elevated sense of smell.
  • Always exhausted.
  • Frequent urination.
  • Dislike towards selective food.
  • A lurking sense of vomiting and nausea.
  • Bleeding or to be more accurate spotting, while the egg implants itself in the uterine lining.
  • An all-time elevated basal body temperature.

Belly at Week 3 of Pregnancy

You will be excited to see minor body changes taking place during the 3rd week of pregnancy, but a growing belly is not one of them. You may feel bloated, but that’s not really because of the growing baby inside. You have quite a few weeks ahead of you till you actually start looking pregnant. So, you can safely preserve your secret until you are ready to tell the world that you are expecting.

Week 3 Pregnancy Ultrasound

At three weeks, your baby is a very tiny fertilised egg called the morula and is as small as a grain of salt. It is also on the move and hence very difficult to be detected during the ultrasound. By the 4th week though, you may be able to see a thicker uterine lining confirming that the little morula has reached its destination and is safe and secure in the uterus for the next nine months.

Week 3 Pregnancy Diet

Before you start eating for 2 people, stop and listen to what the doctors have to say. According to the doctors, a mother to be is only supposed to gain 1 to 2 kg in the whole of the 1st trimester. So, pull back and don’t indulge in excessive eating. Just continue to eat a healthy and wholesome meal with a daily intake of prenatal vitamins, including folic acid. Here are a few diet tips for you:

  • Folic acid is a vital vitamin for the proper growth of the fetus. Therefore, the sooner you start its intake, the better. Whole grain and leafy vegetables are rich in folic acid or folate. So, be sure to include them in plenty in your daily diet. And for extra insurance, please don’t hesitate to take a supplement for folic acid.
  • Avoid junk food as much as possible. Cut down the intake of extra sugar and white flour in any form. Throw saturated fats out of your diet and replace it with salads and grilled meat instead of deep crispy fry food. Junk food, especially fats, increase the risk of pregnancy nausea and vomiting. Therefore, better say no to all kinds of unhealthy foods.
  • Your pregnancy diet for the 3rd week should include lots of leafy vegetables, fruits like apricots, carrots, mangoes, etc., hearty whole grains and low-fat dairy products. Eat and stay healthy for the sake of the little angel growing inside you.
  • Skipping your meals and hurrying through them is a big ‘no’. Relish your meals and start eating a wholesome meal three times a day. This habit will take you a long way and ensure a steady supply of nutrients to your baby, throughout the pregnancy and even later.
  • Scan your dietary habits and get help in case you have an eating disorder. It is important that you consult a dietician before it’s too late.

Week 3 Pregnancy – Tips & Care

The first and foremost tip for week three is to get in touch with a health care provider that you like and trust. This person is going to play a key role throughout your pregnancy; hence, the earlier you identify one, the better. If you are comfortable having a midwife around or a family physician to advise you through and through, then so be it. Here are a few dos and don’ts that you may keep in mind for the third week.


  • Pay attention to your body and lookout for early signs of pregnancy.
  • Get yourself an at-home pregnancy test kit.
  • Eat healthy food with the mandatory inclusion of folic acid or folate in your diet.
  • Eat five servings of fruits and vegetables daily.
  • Go ahead and get a supplement of prenatal vitamin with folic acid.


  • Avoid junk food.
  • Quit smoking, drinking or using drugs.
  • Don’t shop for clothes yet. You will fit into your current clothes for the next few weeks.
  • Don’t take stress at home or at work, especially at this phase. It can hinder the development of your baby.
  • Consult your doctor and avoid taking medicines of any kind.

What you need to shop for?

Your shopping bucket for week 3 stays simple and sweet. Buy yourself a pregnancy book if you haven’t bought one yet. Buy a home pregnancy kit as it will be handy soon. Add a comfortable cotton bra to the list to ease out the soreness of your breasts. That’s all you need for now and for another few weeks into your pregnancy.

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