4 Weeks Pregnant: What to Expect?

Fact Checked Medically reviewed by Tanja Premru-Sršen


During 4 weeks pregnant, the little life you have created, in a form of fertilized egg implants, settles in the inner layer of the uterine wall, where it will continue to grow and develop over your term, which is the next thirty-six weeks. Right now, your growing baby is as big as a poppy seed!

Week four of pregnancy is special because, apart from some other symptoms, it comes with the rise of the pregnancy hormone hCG, which is the main indicator of pregnancy used in the home pregnancy tests. This means that a home pregnancy test might be able to detect your early pregnancy during week four, and you will get a confirmation of your growing baby and baby’s development!

What to expect during the fourth week?

There are so many changes happening in your belly during 4 weeks pregnant, even though it might not seem like it on the surface, since your baby is the size of a poppy seed!

During 4 weeks pregnant, your body is finding ways to adjust to the big new change and the big new role that it is going to take on.

To help ease the stress and uncertainty, keep reading to find out about some of the major changes you can expect during week four of pregnancy.

Physical pregnancy symptoms during week four of pregnancy

It is important to note that every woman’s experience with pregnancy will be unique. In fact, a woman that goes through multiple pregnancies can have a completely different experience every single time.

However, there are some important early pregnancy symptoms you need to note during 4 weeks pregnant because they will help you feel more prepared for the journey. To get informed and prepared, take a look at this list of possible pregnancy symptoms at 4 weeks pregnant.

Light bleeding or spotting

Some women experience implantation bleeding, which is light bleeding or even spotting that happens when implantation happens. Spotting looks like a tiny dot on your underwear, usually light red or pink.

However, if you notice too much blood or if implantation bleeding lasts more than two days, or you have any concerns, make sure to visit your healthcare provider right away, as it could be one of the main early signs of ectopic pregnancy, which needs immediate medical attention.

Feeling bloated and heavy

During 4 weeks pregnant, your body is preparing itself for a baby that it is going to house and grow for the next several months.

During this week, you can expect a bit of bloating. Your uterine lining is getting thicker, making your uterus bigger, which makes you feel more bloated and heavier in the belly area.

Mood changes and overall moodiness

Another main symptom that you (or your partner) might notice at 4 weeks pregnant includes mood swings that seem to come out of nowhere.

These extreme emotions and wild shifts are triggered by increasing pregnancy hormones, and they are the most noticeable in the first and the third trimesters, no matter how many weeks pregnant you are.

Some of the simplest and easiest ways to help yourself feel better during the hormone levels changes and mood swings are relaxation exercises, massages, high-quality sleep, and following a balanced diet.

Tender, painful, and swollen breast

Just like your abdomen, your breasts are starting to prepare for the critical job of nourishing a new arrival at 4 weeks pregnant.

As a result, the number of milk glands increases, and the fat layer also thickens, causing your breasts to enlarge at 4 weeks pregnant. This might also cause breast tenderness and sore breasts.

Morning sickness

There is a big chance that you might experience morning sickness and mild cramping at four weeks pregnant.

There is also a big chance that it might not be limited to the early hours of the day; morning sickness can appear at any time of day or night for women in the early stages of pregnancy.

This condition varies from woman to woman, and some feel only mildly nauseated while others do experience vomiting.

Light-colored discharge

Increased vaginal discharge is relatively common and completely normal for women who are in the fourth week of their early pregnancy.

The vaginal discharge should be sticky, clear, or white. If you happen to experience an itchy or vaginal area or if you notice a bad odor, speak to your healthcare provider.


You should not be surprised if you notice that you feel completely exhausted during your fourth week of pregnancy. In fact, you should prepare yourself for being even more exhausted in the upcoming weeks.

Your body is working all day long to create and support the forming baby, and fatigue is a normal part of pregnancy.

What happens to the baby inside during week four of early pregnancy?

Around weeks four and five of pregnancy, the embryo develops and grows within the womb lining. The cells on the outer level, trophoblast cells, reach out to form links with your blood supply, while the cells on the inner level, embryoblast cells, form into tissue layers.

In just a few short weeks, the placenta will be fully formed, and it will start transferring the nutrients to the embryo.

What happens to a woman’s body during week four of pregnancy?

In week four of the pregnancy, the placenta and amniotic sac are starting to form which are necessary for the baby’s development.

The cluster of cells that will soon become your baby will burrow into your uterine lining, where it will remain for the next several months, growing and turning into your baby.

Pregnancy Checklist During the Fourth Week

There are some steps you should take during week four of your pregnancy, and some of them include:

  • If you have not done so already, take a home pregnancy test. A home pregnancy test is going to prove your suspicions, and a positive pregnancy test is going to make the journey official.
  • Continue taking 400 µg of folic acid every day to support your health and the health of the baby and healthy pregnancy, as well as fetal development.
  • Research the healthcare provider you would like to work with during your pregnancy and baby’s arrival.
  • Do your best to stay calm, and relaxed, and keep your stress levels low.
  • Stop all of the unhealthy habits right away. Quit smoking, avoid secondhand smoke and ditch alcoholic beverages. Stick to a healthy, well-balanced, and diverse meal plan.
  • Start a memory book. If you want to document your pregnancy as a keepsake for you and your kid, now is the perfect time to get it and start filling it with pictures of your bump, special dates, feelings, and other memories.