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3 Weeks Pregnant: A Comprehensive Guide

3 Weeks Pregnant_ A Comprehensive Guide

First of all, congratulations on your pregnancy! Expecting a little bundle of joy is always exciting and nail-biting at the same time. 

But in my experience, knowing what to expect helps me manage the worries that come with the anticipation.

In this article, we’ll be exploring the signs of your baby’s development, your physical bodily changes, and common pregnancy symptoms you might feel 3 weeks into your pregnancy. 

Plus, I’ll be sharing with you reliable tips and tricks I swore by, making these first weeks of pregnancy more tolerable. Let’s get it on!

What Are the Signs of Baby Development at Week 3?

What Are the Signs of Baby Development at Week 3

When I was pregnant for the first time, I hardly believed I was expecting, even when I was already 3 weeks in. 

Similar to when you’re one week pregnant, you still can’t tell you’re pregnant on the outside at this point. But on the inside, critical developments for your baby are already starting.

How Big Is My Baby at 3 Weeks? 

At 3 weeks pregnant, you would have ovulated and conceived. 

This means the winning sperm has made its way through the egg’s outer layer and is fertilized. Your fertilized egg (known as the zygote) also reaches your uterine lining, getting ready for further development. 

Your baby is as small as a pinhead, measuring approximately 0.1 to 0.2 millimeters in length

However, several essential structures are already forming. This includes the neural tube, which eventually becomes the baby’s brain and spinal cord.


Once the zygote travels through your fallopian tubes and enters your uterus, it will then be called a blastocyst. This trip takes about five to six days. 

This process is called implantation, the first significant milestone in your pregnancy journey. 

During implantation, your fertilized egg attaches itself to the uterus where your fetus will receive nourishment and support in the coming months.

During this time, you may experience some light spotting and mild cramping mostly during the day. 

How Will I Know If My Baby Is a Boy or a Girl?

If you’re already wondering on week 3 whether your child will be a baby boy or girl, you’ll have to wait a little longer to find out the answer to that!

Your baby’s sex is determined through the combination of chromosomes from both the sperm and the egg. 

The mother will always provide the X chromosome, making the father the gender-determining factor for providing either an X or Y. An XX zygote means you’ll be having a girl, while an XY zygote will be a boy.

Remarkably, the sex of your baby will already be determined this early. 

However, in current medical technology, parents and doctors will be able to determine the gender of your baby only after approximately 20 weeks through ultrasound or genetic testing.

How Will Your Body Look Like at Week 3? 

How Will Your Body Look Like at Week 3

Many of my friends and family hardly noticed I was expecting during my first few weeks of pregnancy. However, on the inside, I felt very pregnant already!

Here are a few body changes you will subtly see and feel as you progress through the stages of your pregnancy:

The Corpus Luteum and Pregnancy Hormones

After the release of an egg from the ovary, a temporary structure called the corpus luteum forms. 

The corpus luteum produces pregnancy hormones, particularly progesterone and some estrogen.

It helps to thicken the uterus until the placenta takes over in about 10 weeks. This ensures a suitable environment is created for the implanted embryo to grow and develop.

When the soon-to-be embryo is about to be fertilized and implanted in the uterine lining, the placenta starts to take shape. By week 4, the developing placenta will begin to make human chorionic gonadotropin (hCG).

When this happens, traces of hCG can be picked up in blood and urine. This means peeing on a pregnancy test can already accurately confirm your pregnancy a few weeks in. 

You will likely experience a lot of morning sickness at this time too. 

Pregnancy and Sense of Smell

Has your neighbor’s adobo and paksiw smelled a little stronger than usual? If you feel like your sense of smell has heightened this week, it’s a common indication you might be expecting.

According to medical experts, this side effect of pregnancy is caused by estrogen and hCG that magnify even the littlest of fragrances, whether bad or good.

Unfortunately, based on experience, this has caused more morning sickness for me too.

What Are the Common Pregnancy Symptoms at Week 3?

What Are the Common Pregnancy Symptoms at Week 3

My week 3 pregnancy symptoms may not apply to all mommies reading this, but it helps to be wary. Here are a few common pregnancy symptoms you might start to notice at week 3:

Lower Abdominal Pressure

You may feel discomfort and pressure on your lower abdomen. This sensation is pretty normal and should only last for a short while. 

Metallic Taste

Just as your sense of smell is affected by hormonal changes, so will your sense of taste. There might be a lingering metallic taste in your mouth during early pregnancy. This is generally harmless.


The increased production of progesterone, a pregnancy hormone, can contribute to feelings of fatigue and drowsiness.

Breast Changes

I usually notice my breasts feeling tender and swollen when I ovulate during my regular menstrual cycle, but I felt them when I got pregnant too. 

These breast changes are also caused by the hormones preparing our bodies for breastfeeding.

Increased Urination

You may experience frequent urination due to the increased blood flow to the pelvic area and the pressure on the bladder from your growing uterus.

Mood Swings

Just as your menstruation causes mood swings, so does pregnancy. It’s not uncommon to feel more emotional or irritable during this time.

Mild Cramping

You may experience cramping or discomfort similar to menstrual cramps during implantation. This should only occur mildly and briefly. 


Light spotting or slight bleeding can occur during implantation too. This is known as implantation bleeding and is typically lighter and shorter in duration than a regular period.

Tips You Must Consider During This Week

Tips You Must Consider During This Week

As I embarked on my pregnancy journey twice, I managed well with the help of the following tips:

Boost Your Iron and Vitamin C

Take fresh Iemoncito juice, eat lean meats, and incorporate a lot of vegetables into your diet. Adequate iron and vitamin C intake is important for your baby’s development. 

You can find vitamin C in a lot of fruits and vegetables like:

  • Oranges
  • Mangoes
  • Strawberries
  • Melons
  • Bell peppers
  • Tomatoes
  • Asparagus

Meanwhile, iron can be found in many soy products, beef, and poultry. You may also ask your doctor if they think you should take iron supplements.

Avoid Hair Coloring

Hair dye chemicals can pose a risk to your developing baby. So, for caution, skip the salon appointment for a touch-up — at least after your second trimester or week 14.

Go for Healthy Options When Eating Out

I love eating out. But in most cases, indulgent food is not always the healthiest. So, when I got pregnant, I made sure to get healthier options for the sake of my baby. 

I recommend going for salads, grilled proteins, and steamed vegetables. Take note of other foods to eat in your first trimester.

Be cautious of undercooked or raw foods too. These may harbor bacteria or parasites, which can be harmful during pregnancy. So, you’ll have to skip the sushi for a few months.

Take a Pregnancy Test to be Safe

You can wait until you skip a period to take a home pregnancy test. That would just be around week 3 of your pregnancy anyway.  

Pregnancy serum tests are highly accurate and can provide reassurance about your pregnancy status.

If your period is late and you tested negative, retest in a few days.

Choose Calcium-Rich Foods

Incorporate calcium-rich foods such as dairy products, leafy greens, and fortified cereals into your diet.

These foods will ensure that your baby has strong teeth and bones.

Rehydrate and Replenish Your Fluids If Needed

Proper hydration is essential during pregnancy. Aside from water, try diluted juice, clear broth, decaffeinated teas, or hot water with lemon.

Ensure you drink plenty of water throughout the day and replenish any lost fluids because of physical activities or warm weather.

Stock Up on Protein

I made sure to eat at least three servings of protein a day because I know it is crucial for my baby’s growth.

Include a balance of lean meats, poultry, fish, eggs, legumes, and nuts in your pregnancy diet to meet your protein needs.

Recommended Products for 3rd-Week Pregnancies 

Recommended Products for 3rd-Week Pregnancies

There are a ton of maternity products out there that can make your pregnancy journey a convenient one. Here are my top 5 must-haves:

1.  Prenatal Vitamins

Prenatal vitamins that contain nutrients like iron and folic acid are crucial for the baby’s early development. 

It’s actually ideal to take prenatal vitamins even before you know you’re pregnant. 

That’s because the neural tube, which becomes the baby’s brain and spinal cord, starts to form even before you’re aware of your pregnancy.

As such, it’s important to ensure you’re ready with all the necessary nutrients for your baby.

2. Nursing Bra

Trust me. 

Your breasts can be unpredictable when you’re pregnant. So, it’s best to buy high-quality bras that can support your ever-changing breasts!

Find one with superior comfort and structural support. It can also be handy to have one with removable pads and a one-hand drop-down clip for easy nursing when you’re ready to breastfeed.

3. Pregnancy Books

This is especially helpful for first-time moms.

Pregnancy books are ideally full of medically-accurate information that’s easy to understand. They should also contain useful and actionable advice.

Some books have funny and lighthearted reads about moms’ experiences. Meanwhile, others have detailed information about you and your baby.

4. Pregnancy Pillow

Another pregnancy struggle, especially as your belly gets bigger, is getting the best quality sleep. I find myself struggling to find comfortable positions all the time!

Fortunately, pregnancy pillows are designed so moms sleep longer and more comfortably as the baby grows. A maternity pillow should also ideally support your lumbar spine well.

5. Maternity Clothes

Are your regular clothes starting to feel tight and uncomfortable? Insisting to continue wearing them is harmful to your health.

As such, it’s time to shop for maternity clothes!

Don’t worry — you won’t need a completely new wardrobe. Anything that’s loose-fitting and stretchy is good enough.

If you do need to add to your wardrobe, you can even find maternity clothes that are comfortable and stylish at the same time. 


So that’s it, mommies! How is week 3 of pregnancy for you? I hope my experience and tips have been helpful. 

Remember, every pregnancy journey is unique. It is still important to visit a healthcare professional to personally assess your pregnancy progression. 

It’s only just the beginning. Savor the beauty of the pregnancy experience. I wish you well!

Nayna Llenos
Nayna Llenos

Hi, I’m Nayna!
I’ve always wanted to be a mother, and I’m lucky and blessed to have two wonderful children to care for and love.
Despite this blessing, there are times wherein I do wonder if I truly am the mother my children need. Am I giving them the right food, care, and discipline to them?
But that is the beauty of parenting — you grow along with your children as they flourish to be their wonderful selves!
I wish to share my experiences with motherhood and how these tips can help you in your parenting journey.
I hope my advices and experiences will prove useful to you and that you have a smooth and wonderful journey as a mother!