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3rd week of pregnancy

3rd week of pregnancy


The pregnancy calendar starts counting the time from when the last menstruation ended and the egg began to mature. On average, the maturation of the female cell takes two weeks. Hence, the third week of pregnancy is when an already fertilized egg travels from the fallopian tube to the uterus and implantation occurs. The gestational age is measured in obstetric weeks from the date of last menstruation.

Third week of pregnancy

There is no doubt that pregnancy can be one of the most exciting times in a woman’s life but also one of the most troubling. Whether your pregnancy was planned or unexpected, you will have to deal with a whole lot of problems since your body changes in the next nine months. Naturally, you will start thinking about your growing child and how to care for them but you will also experience many physical and emotional changes.

Changes during 3rd week of pregnancy?

Your pregnancy begins when an egg or female sex cell is released from one of the two ovaries on either side of your uterus. The egg then passes through the fallopian tube which is a long duct that runs from the ovary to the uterus. 

The female egg is inside the fallopian tube in a viable state for up to 24 hours and at this time it is fertilized by one sperm. Pregnancy occurs as a result of your partner’s sperm entering your vagina when it ejaculates from the tip of his penis during an orgasm. The spermatozoa contained in the seminal fluid then pass through the vagina and uterus into the fallopian tubes. Sperms vary greatly in the speed at which they swim, so it can take them several days to get to the egg.

Within a few hours, the sperm detects a ready-made egg in the fallopian tube. It largely depends on timing since the egg leaves the ovary about 2 weeks before the next period. The sperm can only survive for up to 5 days after ejaculation.

On average, pregnancy begins after 14-16 days of the cycle. This means that there is a fairly short window of opportunity during which conception can occur. But the period of ovulation can vary slightly – it can be 17 days from the first day of last menstruation (if the cycle is about 32 days), or even late ovulation – with conception for a period of 18-19 days.

15-21 days of pregnancy

As soon as a sperm enters it, the structure of the egg changes so that no other sperm can enter. A fertilized egg or zygote (or two zygotes in the case of fraternal twins) begins to actively divide and moves from the fallopian tube to the uterus within a few days. At the time, it was a tiny ball of a few hundred cells called a blastocyst. With an average cycle length of 28 days, this is a pregnancy of 16-18 days.

The next task is to attach to the lining of the uterine wall (endometrium), which serves as a source of oxygen and nutrients. Some of the blastocyst cells develop into a placenta (or two). During the implantation period which is day 21 of pregnancy (when the blastocyst implants into the endometrium), human chorionic gonadotropin (hCG) is released, which causes increased estrogen production and progesterone and prevents the eggs from maturing in the ovaries. From this moment on, the menstrual cycle stops. Implantation is also possible in 17-18 to 19 days. You will have identical twins if the egg divides into two embryos before implantation. With the simultaneous fertilization of two eggs, the birth of twins (fraternal twins) is possible.

What happens to baby at 3rd week of pregnancy?

From what we have already mentioned, you will notice that it is very difficult to say exactly when conception occurred. You know that the egg will be released from the ovary about 2 weeks before the next period, but it is impossible to know the exact time when this will happen. On top of that, it can take anywhere from 30 minutes to several days for your partner’s sperm to reach your fallopian tube. The problem of not knowing when conception occurred is solved by doctors who calculate pregnancy not from conception, but from the start of your last menstrual cycle. As strange as it may seem, your doctor calculates your pregnancy even before you get pregnant!

A baby at 3 weeks of development is called an embryo and exists as a tiny collection of about a few hundred cells rapidly dividing and will continue to develop over the following weeks and months. The outer cells develop into the placenta, which provides your baby with nutrition and other functions, while the inner cells develop into the fetus.

As you might expect, the embryo is tiny in the third week of pregnancy: no bigger than a pinhead! But the development of the fetus does not stop for a second. In the first 3-4 weeks of pregnancy, implantation occurs with the formation of the placenta rudiment, the laying of the main tissues from which organs and systems will then develop.

What happens to body at 3rd week of pregnancy?

You are very early in your pregnancy, so don’t expect the development of the fetus to affect how you feel. Remember that at 3 weeks, there is not even a delay, and you may not suspect that you are pregnant. Even if you have tried to conceive with your partner, you will not find any physical signs at 3-4 weeks of pregnancy that would indicate that you have a little man growing inside you.

Is it possible to determine pregnancy at 3 weeks using tests?

Yes. The level of hCG hormone is already detectable by the third week of pregnancy and a pharmacy test strip will produce a positive result. Additionally, your status can be validated by blood tests for hCG. At the second week of gestation, an ultrasound of the fetus has yet to be revealed. However in the third week it will demonstrate that a new life has formed in the woman’s body, albeit the child will only be a tiny speck on the screen.

These days, home testing kits are just as precise as a medical clinic’s urine or blood test, and much more convenient. However, the time frame for accurate results is still too short, so if the outcome is negative, don’t assume that you are not pregnant – it is likely that you tested too soon. The tests will be more precise if you wait a few days to a week after your period is due and you are late.

Do you need Ultrasound at 3 weeks of pregnancy?

A scan at 3 weeks of pregnancy is too early to detect a fetal egg, as it is too small to be seen. In most countries, the first ultrasound is conducted between 8 and 14 weeks, with a follow-up scan at 18-21 weeks. In exceptional cases, a scan may be required if the woman experiences stomach pain or discharge that could point to potential pathologies.

3rd week of pregnancy symptoms

By the 3rd week of pregnancy, most of the tell-tale signs of an “interesting situation” become apparent. Many women feel their breasts become fuller and sore during this time, and their nipples darken slightly. 3rd weeks from conception, the initial symptoms of morning sickness may be present. Some foods may suddenly seem more desirable, while others become repulsive. This is also the case with smells. Nausea may not be limited to the morning but may continue throughout the day.

In addition, some other symptoms are observed at the 3rd week of pregnancy.

  • Fatigue and drowsiness: These are due to hormonal changes and the fact that the body spends energy resources on the baby’s development.
  • Pain or cramps in the lower abdomen: They appear when the fetus attaches to the uterus or when it stretches. If the pain is barely noticeable, then you should not worry. If discomfort is felt, consult a doctor, this may be a symptom of a frozen or ectopic pregnancy.
  • Minor vaginal discharge: Usually these are brownish smears that a woman finds on her underwear. Sometimes such discharge is confused with the onset of menstruation, but they most often indicate that the embryo is safely fixed in the uterus.
  • Bloating: It is caused by hormonal changes and changes in the expectant mother’s diet.
  • Breast Sensitivity: Sensitivity and even soreness of the breasts.
  • Mood swings are influenced by hormones.
  • Frequent urination: This is since a pregnant woman usually drinks more fluids, and the kidneys work more actively.


The absence of a menstrual period is the main sign of pregnancy 3 weeks after conception. If you have an ordinary 28-day cycle, it should begin this week. If you have unusual sensations in your lower abdomen and chest pain, it is time to purchase a pregnancy test. By 3rd week of pregnancy, the test will be able to show whether you are pregnant or not.

Stomach ache

Pregnant women in the early stages may feel discomfort in their lower stomach area, similar to the pain some people experience before their period. Unless the pain is severe and causing distress, there is no need to panic; it could be brought on by a visit to the gynecologist, sexual intercourse, or due to hormonal changes affecting the bowels.

If the pain does not subside, it is advisable to inform your gynecologist. Sudden, sharp pains may indicate cervical erosion or more serious conditions, like a frozen or ectopic pregnancy. If other symptoms are present, such as spotting or changes to the cervix, it is likely a case of threatened abortion and requires immediate attention.

Research has shown that women who suffer from abdominal pain in the early stages of pregnancy (before 12 weeks) have a greater risk of placental abruption, neonatal hypoxia, and postpartum endometritis. Hospitalization is likely to be necessary in such cases. Therefore, it is essential to take care of yourself properly during pregnancy, and to try and avoid feeling stressed or anxious. For a period of 3-4 weeks, ectopic pregnancy can also make itself felt. 

At this time, the embryo, if it is developing outside the uterus, begins to cause discomfort and stretch the tissues, usually on the left or right side of the lower abdomen, where the fallopian tubes are located. This is partly why pain during an ectopic pregnancy is often confused with appendicitis. If you experience this kind of pain, you must consult a gynecologist or go for an ultrasound. An ectopic pregnancy is dangerous and should be terminated as soon as possible. 

Brown discharge

At the 3rd week of pregnancy, a variety of changes can appear for the mother, including a brownish discharge which is usually insignificant, signifying that the embryo has attached to the uterus. However, if the discoloration is bright red or accompanied by abdominal pain, a miscarriage may be imminent. Fresh bleeding is particularly concerning, as it could mean that the uterus has rejected the fertilized egg. In such a case, medical attention must be sought and an ambulance should be called.

Do’s and Don’ts of 3rd week of pregnancy

A woman should pay extra attention to her well-being from the very beginning of her pregnancy. By the third week, it may not be noticeable yet, but this is the most critical time for the formation and growth of the fetus.

Do’s of 3rd week of pregnancy

  • Continue to work: if the career is not related to heavy physical labor. You should not perceive your condition as a disease from 3 weeks. With good health, it is recommended to go on sick leave only after 30 weeks; if desired, you can later.
  • Take folic acid: Multivitamin complexes at 3 weeks are usually not yet prescribed, but folic acid is very important. Even if a woman is not yet going to a gynecologist, you should start taking vitamin B9.
  • Lift no more than 3 kg: Do not completely abandon the physical activity. However, carrying heavy weights is already dangerous. Therefore, doctors usually allow you to lift 2 to 3 kg at a time.
  • Have fun while feeling good: Do not deny yourself a trip, a hike, or a long and exciting walk. You can meet with friends, go to a cafe.
  • Lead an intimate life: If pregnancy occurs, this does not become a reason for refusing sexual intercourse. In the absence of problems, they will even benefit, as they will increase blood circulation in the pelvis and cause a jump in the hormone of happiness.

Don’ts of 3rd week of pregnancy

  • Drink alcohol, smoke and take drugs. It is worth eliminating all bad habits from your life as early as 3 weeks of pregnancy.
  • Drink medication on your own. Even pills for headaches and fever can be dangerous for a child.
  • Get stressed. Nervous tension causes an increase in cortisol and adrenaline. The unborn baby does not need these hormones.
  • Overstress physically. Heavy lifting, complex sports loads and sudden movements can cause an increase in uterine tone.

Proper nutrition for 3rd week of pregnancy

The pregnant woman should ensure she is receiving the correct nutrition during the whole period of pregnancy. Most micronutrients can be obtained by consuming food, which helps form the baby’s systems and organs and prevent any pregnancy-related issues.

In the 3rd week of pregnancy, it is recommended:

  • Eat lots of dairy products. Soon, the active form of the musculoskeletal system will begin, and the child needs calcium. It is in large quantities in cheese, cottage cheese, kefir, sour cream, and fermented baked milk. Also, fermented milk products restore intestinal microflora, which becomes a good prevention of constipation.
  • Eat meat or fish daily. Animal products contain large amounts of protein. It is needed by a pregnant woman and her unborn baby. Protein foods prevent weight gain. For a child, protein ensures proper cell division.
  • Have vegetables and fruits in your diet that are in a particular season. They contain a large number of useful substances and vitamins. Vegetables and fruits are also a source of fiber. They normalize bowel function and ensure proper digestion.
  • Eat complex carbohydrates for breakfast and lunch. They do not cause a jump in sugar, which is not desirable in the 3rd week of pregnancy. Complex carbohydrates energize the body and help to cope with apathy and drowsiness. You can get them from pasta, cereals, and whole-grain bread.
  • Sweets and muffins can also be consumed at week 3. In addition, many women are drawn to sweets in the early stages. However, you need to know the measure and not lean on sugar. Excessive consumption of treats causes a jump in insulin and can cause diabetes in pregnant women.
  • Drink a sufficient amount of water. It is recommended to drink at least 1-1.5 liters per day. Water saturates the cells, makes the skin more elastic and prevents the appearance of stretch marks. Also, the drinking regimen at week 3 prevents constipation and gas formation.

What is early toxicosis?

During the 3rd week of pregnancy, some women undergo toxicosis due to the restructuring of the hormonal system and shifts in the functioning of the nervous system. Toxicosis is usually indicated by nausea and vomiting (frequently in the morning), along with fatigue, weariness and sleepiness. Other types of toxicosis, such as dermatosis, can cause itching in the woman’s skin. Pregnant women may sometimes have muscle cramps or aches in their limbs.

What can not be done at 3rd week of pregnancy?

Generally, it is essential to quit bad habits, particularly drinking alcohol and smoking cigarettes during 3rd week of pregnancy. Additionally, it is necessary to alter the diet to healthier options, steering clear of spicy, fried, and salty dishes. Owing to the chance of miscarriage at 3 weeks, pregnant women are advised to abstain from strenuous physical activity, such as lifting heavy items, and from getting overwhelmed with stress.

Is it possible to have sex at 3rd week of pregnancy?

Yes. Your doctor may advise otherwise, but it is generally safe to continue your sexual life as normal during pregnancy. Intimacy will not harm the fetus, and the uterus walls will protect him. Hormones in the early stages may result in a lack of desire for intercourse, but if the desire is still there, the body needs it. 

You should not deny yourself of sexual pleasure but rather prefer sex that doesn’t require excessive physical exertion. Your pleasures will not harm the embryo as the mother’s womb will protect him from any outside influences.