4 Weeks Pregnant

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4 Weeks Pregnant

There’s still a long way to go at 4 weeks pregnant, but there’s plenty to talk at this stage. You may start noticing some early signs of pregnancy at week 4, and your baby will be well on its way to development.


This is a good time to recap on what has happened to your body so far. In the first 2 weeks of pregnancy, you were not actually pregnant, you are only deemed pregnant as it is easier for medical practitioners to calculate the due date from the first day of your last cycle. In week 3, you experienced ovulation and the fertilization of the egg, which has now formed into small cluster of cells in preparation for the development of the embryo and the placenta.

Now, your 4-week embryo will continue to make a home for itself inside your womb, as it moves from the uterine tube to the uterus, and your ever-increasing baby will start to make changes to your body that will unfamiliar.

4 Weeks Pregnancy Symptoms

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4 Weeks Pregnancy Symptoms

There are a few things that you can look out for as early signs of pregnancy at week 4, here are some of the most common ones:

  • Missed period
    One the best ways to know if you are pregnant after 4 weeks is whether you have missed your period. Yet, if you have, pregnancy is not a certainty. There are many reasons that your menstrual cycle can be irregular and if you’ve missed your period at week 4, you should take a pregnancy test before reaching any conclusions.
  • Implantation Bleeding
    Light bleeding, or spotting, can be a sign that your 4-week embryo has been implanted into the wall of the uterus. Only a small number of pregnant women experience this symptom, so if you don’t, it doesn’t mean that you are not pregnant. For those that do, the blood may be a light pink or light red color, and it usually happens slightly earlier than your expected period date.
  • Nausea and vomiting
    Another early sign of pregnancy in the first 4 weeks is increased feelings of nausea or vomiting. If you are experiencing this, don’t worry, this is normal, and many women feel nauseated in the early stages of pregnancy.
  • Fatigue
    Many women feel unusually tired during when they are 4 weeks pregnant, and this is largely due to the rapidly fluctuating level of hormones in your body. Make sure you try and get plenty of rest if you are experiencing this early symptom of pregnancy at week 4.
  • Tender breasts
    A common symptom of pregnancy is soreness in the breasts. If they feel particularly tender and are causing you discomfort, it could be an indicator that you are pregnant, and you may want to look out for other early signs of pregnancy.

Your Body at Week 4

It’s very likely that you won’t notice any changes to your body when you are four weeks pregnant, but there are some changes that will be happening internally.

Although the baby is still at a very early stage and the fetus at 4 weeks is still tiny, your body is making changes and getting ready for one of the most intense experiences that it will experience throughout its lifetime. During this week, the uterus and zygote (fertilized egg) will have made contact, with the soon-to-be baby attaching itself to the lining of the uterus. This may cause spotting, or implantation bleeding, but it is not too common.

After fertilization, the egg will start releasing a pregnancy hormone called human chorionic gonadotropin, or hCG. This is the hormone that is eventually responsible for making a positive pregnancy test, and it also communicates with the corpus luteum to let it know that it is needed to nourish the zygote until the placenta has been formed at around week 10 of the pregnancy.

Baby Size at Week 4

At this stage of the pregnancy, your baby will be the size of a poppy seed and will be roughly 2mm in length.

In other words, it will be very tiny and will be unnoticeable to you, or anybody else, from the outside.

Baby Size at Week 4

Photo by Klemen Vrankar on Unsplash

Week 4 Pregnant Ultrasound

Your baby will barely be noticeable when you are 4 weeks pregnancy, and an ultrasound is not normally carried out until much later in the cycle. It is worth noting that, when you do eventually have an ultrasound, the medical practitioner may modify the start date of your pregnancy, as it provides more accurate information on the due date.


Experiencing pregnancy symptoms at week 4 is not common, and it you may not notice any early signs of pregnancy until much later. Yet, some women feel discomfort in their stomach when they are 4 weeks pregnant, and this is likely due to the embryo implantation.

There is not too much you should expect in terms of 4 weeks pregnant symptoms. It is likely that you won’t even know you are pregnant at this stage but, if you suspect that you are, the best course of action is to remain calm, eat healthily, and consult your doctor with any concerns that you may have.

You might feel slightly nauseated, fatigued, and/or have tender breasts and a sore stomach. Though, most women don’t feel this until later.

As the fetus at week 4 is only the size of a poppy seed, your stomach will not look any different to usual. All the changes that you are experiencing will be internally, as opposed to externally, and they wont be noticeably visible.

Tips for Week 4 of Pregnancy

  • Get plenty of Vitamin D
    It’s a good idea to pay extra care to your nutritional intake when you are pregnant, and a vital component of a healthy diet is Vitamin D. This will help both you and your baby-to-be maintain and develop strong bone structure. Good sources of Vitamin D are milk, eggs, and the sun. It is best not to use supplementations when you are four weeks pregnant, unless you have consulted your doctor first.
  • Healthy fats
    Getting the right amount of healthy fats is crucial for the development of your baby, particularly omega-3 fatty acids. These can be found in flaxseed, walnuts, and certain types of fish.
  • Take a pregnancy test
    If you think you are showing early signs of pregnancy at week 4, take a pregnancy test. It still might be too early to show as positive, but for some women it can show 2 weeks after conception.

By Editorial Team

NetParents is the go-to resource for all parenting issues. We are an independent body that seeks to offer general information on various parenting topics and unbiased reviews on baby products.

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