Calculate Pregnancy Week

Due Date Calendar

The Due Date Calendar gives you an overview of important dates and appointments during pregnancy. Starting with the date of fertilization, through important screening dates and stages of your child's development, the pregnancy calendar also gives the start date of maternity leave and the date of the calculated date of birth.

For your baby's development, the pregnancy calendar gives dates of heartbeat, complete organ attachment, sex, noticeable movements, hearing development and finished development depending on the date you were fertilized and your your cycle length.

Please note that the pregnancy calendar is similar to our Pregnancy Week Calculator. We have additionally listed it here as a "Due Date Calendar" to make it easier for parents-to-be to find our calculators from the Medicine and Health section on the internet.

In addition to the pregnancy calendar, the Birthdate Calculator might also be of interest to you.

Our pregnancy calendar gives you a preview of an exciting time

Pregnancy is an exciting time that brings many changes. With every passing month and week, exciting things happen in your body. Our pregnancy calendar shows you what is happening to you and your baby in your belly during each week of pregnancy.

How our pregnancy calendar works

To find out which week of pregnancy you are in using our pregnancy calendar, we only need two pieces of information:

  • the first day of your last period and
  • the average duration of your cycle.

Simply input this data into the calculator, click on "Calculate" and find out which week of pregnancy you are currently in.

The Due Date Calendar - week by week at a glance

Over a period of 40 weeks, a little complete human being grows inside you. Find out now what happens in your body week by week.

Pregnancy Week 1: A new cycle begins

Every pregnancy starts with a new cycle. In most cases, this lasts 24 to 36 days, but fewer or more days are also possible. The cycle starts when your period starts and ends the day before your next period starts. Although no embryo has been implanted in the first week of pregnancy, this is added to the total duration of the pregnancy.

Pregnancy Week 2: The fertility phase

In the second week of pregnancy, no embryo has taken root yet either. This is the fertility phase. The ovaries are working at full speed, with up to two follicles maturing to contain an egg.

Pregnancy Week 3: The pregnancy begins

The third week of pregnancy is the beginning of pregnancy. The sperm fertilizes the egg, which now seeks a cosy place in the uterus. Here, it divides diligently, and an embryo is formed.

Pregnancy Week 4: As small as poppy seeds

In the fourth week of pregnancy, your baby is as tiny as a poppy seed. And yet it already evokes many feelings of happiness. The positive pregnancy test can now be the first moment of a life full of changes.

Pregnancy Week 5: A little heart beats

Pregnancy is still very fresh, and many things feel new and perhaps unfamiliar. Although you won't feel much of the tiny embryo in the fifth week of pregnancy, its little heart is already starting to beat. Sometimes, this can be seen on an ultrasound at this early stage of pregnancy.

Pregnancy Week 6: Twice as big

For about four weeks now, the little person in your belly has been growing. It is still tiny, but it can already do great things. The embryo has already doubled in size and gained weight.

Pregnancy Week 7: First movements

Although it will still be a few months before you can feel your baby's first tentative movements, it can already move very well now. These movements are still uncontrolled and serve to build up muscles.

Pregnancy Week 8: Sense of purpose develops

Humans have five senses: hearing, seeing, feeling, tasting and smelling. These senses are enormously important for personal development. In the eighth week of pregnancy, the eyes and inner ear are laid out—two important foundation stones for the senses.

Pregnancy Week 9: All the important organs are laid out

Pregnancy week nine marks the beginning of the third month of your pregnancy, and the first trimester is now coming to an end. All the important organs of your “little miracle” are now laid out and the embryonic phase is over. From a medical point of view, the baby is now called a foetus until birth.

Pregnancy Week 10: An almost perfect human being

At about three centimetres, the baby is still very small (almost like a perfect human). Toes and fingers have formed more and more, the head has straightened up and the face is also already recognisable.

Pregnancy Week 11: Sensory organs are developing

In the eleventh week of pregnancy, the baby is still very small but already quite developed. The phase of organ development is now almost complete, and now the sensory organs are in the foreground. The function of the nose and mouth continues to develop, and the taste buds are also developing.

Pregnancy Week 12: Attachment of the tooth buds

The first trimester is slowly coming to an end, and the critical phase of pregnancy is now almost over. A little human being has developed, with all the organs as well as fingers and toes. Now the finishing touches begin, the first tooth buds are laid down. These will later give rise to the small milk teeth.

Pregnancy Week 13: Maturation and growth

In the first few weeks of pregnancy, the foundations for the baby's development were laid. The organs have been laid out and have grown, and little things like finger and toenails have also formed. Now it’s time for the baby to grow.

Pregnancy Week 14: Growth of the lanugo hair

In the 14th week of pregnancy, the little baby's body is covered with soft lanugo hair. This protects the skin and falls out before birth. Nevertheless, there are also babies who still have the hair on their skin at birth.

Pregnancy Week 15: The baby perceives mum's voice

The 15th week of pregnancy is a real milestone for the baby. His hearing has developed to the point where he can clearly hear his mother's voice. But the expectant mother’s heartbeat is also audible to the baby and has a very calming effect.

Pregnancy Week 16: Hormones on the rise

From the 16th week of pregnancy, the baby's thyroid gland is working at full speed because, at this time, important hormones are produced for development. At this point at the latest, expectant mothers should take enough iodine to support the little person's thyroid gland.

Pregnancy Week 17: Muscle training, thanks to lots of activity

The baby moves a lot and with pleasure from the 17th week of pregnancy. The movements are now becoming more controlled. The baby can now move its arms and legs in a certain direction.

Pregnancy Week 18: Growing while you sleep

Many expectant mothers feel that their baby is always active at about the same time. Until the 18th week of pregnancy, there is no fixed rhythm yet. The baby still sleeps a lot and takes about 20 hours a day to grow in peace.

Pregnancy Week 19: The sense of touch is developing

The baby is already developing its sense of touch while in the mother’s tummy, which is well developed in the 19th week of pregnancy. With its little hands and feet, it now repeatedly touches the womb and thus learns the limitations in the mother’s belly.

Pregnancy week 20: Enjoyment with all senses

Pregnancy Week 20 is another important milestone in the development of the baby. The senses of smell, taste, touch and hearing are now becoming more developed. Vision is also developing further. The eyes now also react to bright light, although they are still closed.

Pregnancy Week 21: The sleep-wake rhythm develops

The baby still sleeps about 20 hours a day. And this sleep is also important, as all developmental steps are peak performance for the little body. However, certain waking phases now appear and a sleep-wake rhythm develops.

Pregnancy Week 22: Attention "Hiccups"

Although the baby has been hiccupping for some time, it is usually noticeable for the first time in the 22nd week of pregnancy. Because of its size, the hiccups may hit the abdominal wall, depending on the position in the abdomen.

Pregnancy Week 23: Distinguishing sounds

In the 23rd week of pregnancy, the inner ear bone develops in the baby. Until now, this had not yet hardened and the baby could not distinguish sounds from each other. Now, this is becoming more and more possible as the bone hardens more and more.

Pregnancy Week 24: What does mum eat?

The baby's taste buds are already well developed. In the 24th week of pregnancy, it can now also distinguish between different tastes. It swallows amniotic fluid and can tell whether it is sweet, salty or sour.

Pregnancy Week 25: Balance training

For infants, balancing their posture is a huge challenge to learn. The foundation is already laid with the development of the sense of balance in the 25th week of pregnancy. The baby is now increasingly able to influence its posture itself.

Pregnancy Week 26: The umbilical cord as a toy

The baby likes to use the umbilical cord as a toy. The baby catches it, grabs it and tries to move it with its little hands and toes. In this way, it not only provides its own entertainment but also trains the grasping reflex.

Pregnancy Week 27: Formation of the brain furrows

The brain is in focus in the 27th week of pregnancy. Until now, its surface has been rather smooth. Now, this is changing from day to day; brain furrows are forming. As a result, the baby will now soon experience its first dreams.

Pregnancy Week 28: Fine-tuning the brain

In the 28th week of pregnancy, furrows continue to form in the brain. As brain activity increases, these also continue to increase. This allows sensory perceptions to become more differentiated.

Pregnancy Week 29: It's all about the bacon

This is more precisely the baby fat because, in the 29th week of pregnancy, the development of the organs is as good as complete. Now it's all about weight gain and length growth. In the 29th week of pregnancy, the baby weighs about 1,200 grams and is 38 centimetres long. So, until birth, it still has to grow a little. Afterwards, it then weighs on average about 3,400 grams and is 50 centimetres tall.

Pregnancy Week 30: Perception of pain

Researchers have found that 30 weeks of pregnancy is also an important milestone in the baby's development. It can now perceive pain stimuli and also feel pain.

Pregnancy Week 31: Breathing takes centre stage

A very important time in terms of breathing is the 31st week of pregnancy. In its maturation, the lungs have progressed to the point where they can inflate. Now the production of surfactants also continues to increase and the lungs can no longer stick together.

Pregnancy Week 32: Finding the right position

For a long time, the baby had a relatively large amount of space in the belly. However, that is now slowly changing. Although there is still enough room for turning, it is getting tighter and tighter in the mother's belly. That is why many children already assume their final birth position in the 32nd week of pregnancy.

Pregnancy Week 33: Brain Growth

In the 33rd week of pregnancy, the brain is already well developed. However, there is still a lot happening in the coming weeks. The circumference of the head continues to increase as the volume of the brain increases significantly.

Pregnancy Week 34: Lung maturation is complete

The lungs in particular are always a concern in premature births. Up to the 34th week of pregnancy, mothers in preterm labour are given a lung maturation injection to help the lungs develop. From the 34th week of pregnancy, lung maturity is complete and the baby (if it is born now) can breathe on its own.

Pregnancy Week 35: The baby's dreams

We have already mentioned that dreams are possible earlier. With the 35th week of pregnancy, a time begins when it can even dream very intensively. Unborn babies already even have a REM phase as discovered by researchers.

Pregnancy Week 36: Taking the starting position

In the 36th week of pregnancy, expectant mothers want their baby to have assumed the correct birth position (that is, the cranial position). According to doctors and midwives, babies have time to do this by then. But if this has not happened so far, only then can you attempt to lure the baby into the right position.

Pregnancy Week 37: Increase in brown adipose tissue

The baby has gained a lot of weight in the past few weeks of pregnancy and has also put on a lot of fat deposits. The fat reserves have increased significantly by the 37th week of pregnancy.

Pregnancy Week 38: Final touches to the lungs

Even if lung maturity is already complete and the baby is ready to be born in the 38th week of pregnancy, a few more days in the belly will do no harm. Here, final touches can still be made to the lungs as they now begin to produce cortisone.

Pregnancy Week 39: Fat reserves are stored

With the beginning of the 39th week of pregnancy, it can start at any time. The baby is ready for birth. As long as it is still in the womb, it will put on more fat reserves until birth.

Pregnancy Week 40: Waiting for the starting signal

Having reached the 40th week of pregnancy, the pregnancy is now almost complete. The small poppy seed has now become a strong little human being. This one can now set off at any time.


Source information

As source for the information in the 'Week of pregnancy' category, we have used in particular:

Last update

This page of the 'Week of pregnancy' category was last edited or reviewed by Stefan Banse on February 19, 2023. It corresponds to the current status.

Changes in this category "Week of pregnancy"