Young woman holds a pregnancy test in her hands.

Pregnancy Weeks

Pregnancy Week 4

The Delicate Phase

In week 4 of pregnancy, the baby is a tiny little ball of cells. Here, we tell you what signs of pregnancy might appear and why you should take particular care of yourself now. 

What's Going On in Your Belly Right Now?

The tiny ball of cells, also called a blastocyst, burrows deeper into the uterus. The yolk sac, amniotic cavity, and placenta begin to develop. The placenta supplies the baby with oxygen and nutrients while simultaneously removing metabolic waste. 

Your baby is still microscopically small: it is the size of a poppy seed.

Your baby is still microscopically small: it is the size of a poppy seed.

The pregnancy hormone HCG (human chorionic gonadotropin) is being produced. Among other things, it ensures that the mucous membrane remains well intact, and that no menstrual bleeding takes place.

External influences such as infections, medication, excessive stress, alcohol, or nicotine can disrupt the pregnancy or damage the embryo at this stage. A spontaneous abortion may occur (a miscarriage before week 13 of pregnancy). Since the bleeding can be like a heavier menstrual bleed, it is possible for some women to never realize that they were pregnant at all.  

If everything goes according to plan, the cells of the blastocyst will start to specialize. However, at this time an ultrasound would only show the amniotic cavity as a shadow. 

How Do You Feel at 4 Weeks Pregnant?

Although you may still feel "quite normal", you are currently in a very delicate phase of pregnancy. It is therefore important to take special care of yourself: Protect yourself from infections by maintaining good hygiene, avoid unnecessary stress, get plenty of sleep, and eat a healthy diet.

In the kitchen and when eating in particular, take care to avoid illness due to listeria and toxoplasmosis. Food should be heated up fully and/or washed thoroughly. Avoid unpasteurized dairy products, raw meat, raw fish, and cured meats. 

The higher progesterone level causes a slight increase in temperature, the mammary glands become denser, and more fluid accumulates in the tissue – many women recognize this as signs that their period is imminent.  

Painful breasts and very sensitive nipples are some of the most common first signs of pregnancy. Severe fatigue and a frequent urge to urinate may also indicate successful implantation. 

If you record your cycle by monitoring your temperature, you may find that the temperature peak lasts longer than usual. If it exceeds 18 days, you can usually assume that you are pregnant.

Early tests can now also indicate pregnancy by measuring the concentration of HCG in urine. Your HCG levels are particularly high in the morning, so it is best to take a test immediately after you get up. If the test doesn't show up as positive yet, this does not necessarily mean that you are not pregnant! The quality of the tests and your hormone production can fluctuate, so it is important to be patient. 

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