Week 3 Pregnancy: The Beginning of Fertilisation

In week 3, pregnancy begins when the sperm fertilises the egg, creating a tiny cell called a zygote. This zygote travels down the fallopian tube to the uterus, where it will implant and grow.

Wondering about what happened before fertilisation? Learn about ovulation and how your body prepared for conception in week 2 of pregnancy.

Week 3 body changes

If your egg has been successfully fertilised, congratulations — you are now pregnant! Your body is preparing to host the fertilised egg, which is rapidly dividing and progressing through the fallopian tubes toward the uterus. Upon successful attachment to the uterine wall, you may experience light spotting, known as implantation bleeding.

At this early stage, the embryo is still too small to cause significant physical changes in your body. It is important to increase your intake of essential nutrients, such as folic acid, protein, calcium, iron, and vitamin D, as prescribed by your doctor. These supplements will support both your health and the development of your baby.

Week 3 pregnancy symptoms

Many women may begin to experience pregnancy symptoms as early as 3 weeks, while others may not, so don't worry if you're on either end of the spectrum.

One of the most common symptoms at this point is light spotting, known as implantation bleeding, which occurs when the fertilised egg attaches to the uterine wall. This bleeding may appear pinkish or brown in colour.

In addition, you might also experience other pregnancy symptoms such as:

• Nausea
• Fatigue
• Cramps
• Breast tenderness
• Darker nipples
• Implantation bleeding, although not experienced by everyone, is common and might be confused with menstrual blood.

Your baby at week 3

During this week, you may not feel it, but a baby is beginning to form inside you. The fertilised egg continuously divides into numerous cells as it travels through the fallopian tube toward the uterus, a journey that takes about three days.

Upon reaching the uterus, this cluster of cells becomes a tiny, fluid-filled ball known as a blastocyst. The blastocyst then settles into the uterine lining, where it will grow and develop over the next nine months.

This stage marks the formation of an essential connection between the developing embryo and the mother’s body, ensuring that nutrients are accessible and wastes are removed. Over time, the implantation site will develop into the placenta.

At this stage, the blastocyst is incredibly small, measuring approximately 0.00019 inches long. However, your baby is poised to begin growing rapidly.

Early pregnancy testing

This is the week when the placenta begins to develop and start producing the pregnancy hormone human chorionic gonadotropin (hCG). By now, there should be enough hCG in your bloodstream to yield a positive test result. In earlier weeks, hCG levels might have been too low to detect.

If you still aren’t testing positive, don’t worry. hCG levels can take time to increase and might not be detectable until 5 to 6 weeks.

Once your pregnancy is confirmed, there are additional tests and screenings to consider during the first trimester, but these will come in the later weeks. For now, enjoy the early stages of your pregnancy and ensure you get plenty of rest!

When should you see a doctor to confirm your pregnancy?

Discovering you're pregnant is an exciting moment, but it's essential to know when to seek professional medical care. If you've taken a home pregnancy test and received a positive result, here's guidance on when to consult a doctor:

1. After a positive home test

   • Generally, wait about a week before booking an appointment with a gynaecologist. This allows time for the pregnancy to be visible on an ultrasound scan, typically around 6-7 weeks of gestation.

   • If you have irregular menstrual cycles, consider seeing a doctor sooner to confirm the pregnancy and assess its viability.

2. Immediate medical attention

   • Seek medical care promptly if you experience any unusual symptoms such as vaginal bleeding, severe abdominal pain, or extreme nausea, regardless of how far along you think you are.

At Thomson Medical, we understand the importance of timely and comprehensive prenatal care. Our team of obstetricians and gynaecologists at Thomson Specialists and Thomson's Women Clinic are here to support you from the moment you suspect you're pregnant. Remember, every pregnancy is unique, and our team is here to address your individual needs and concerns.

Request an appointment with Thomson Medical today to begin your pregnancy journey with compassionate care and support.

Preparing for week 3 of pregnancy 

In Week 3 of pregnancy, your body is undergoing important developments that lay the groundwork for your baby's growth. Here's how you can get ready and optimise this important stage:

• Keep up with prenatal vitamins: 

  • Continue taking your prenatal vitamins, including folic acid, iron, calcium, and vitamin D, to support both your health and your baby’s development.

• Eat well: 

  • Nourish your body with a balanced diet full of fruits, vegetables, whole grains, and lean proteins. Steer clear of alcohol, tobacco, and excessive caffeine.

• Stay hydrated: 

  • Drink plenty of water to keep yourself well-hydrated and energised.

• Stay active: 

  • Engage in moderate exercise like walking or yoga to keep your body fit and ready for the journey ahead.

• Watch for symptoms: 

  • Be aware of early pregnancy symptoms, such as light spotting, fatigue, or breast tenderness, as your body adjusts.

• Prioritise rest and relaxation: 

  • Ensure you get plenty of rest and find ways to manage stress, whether through relaxation techniques or activities you enjoy.

• Track your cycle: 

  • Keep an eye on your menstrual cycle and ovulation to understand your body’s changes and the optimal times for conception.

Curious about what’s next in the upcoming weeks? Read more about the formation of your baby in week 4!

The information provided is intended for general guidance only and should not be considered medical advice. For personalised recommendations and tailored advice, please consult a specialist at Thomson Medical. Book an appointment with Thomson Medical today.