Pregnancy Week-by-Week Guide: What to Expect From First Day

Week-by-week pregnancy guide: Learn what to expect during pregnancy from conception to delivery, including symptoms, signs, baby growth, and milestones.

Pregnancy is an incredible journey filled with excitement, transformation, and discovery. From the moment of conception to the first time you hold your baby, each week brings something new. Whether you're a first-time parent or expecting again, understanding the pregnancy week by week changes helps you stay informed, prepared, and connected to your baby’s development.

This pregnancy guide breaks down each week with helpful information on fetal growth, pregnancy symptoms, body changes, and what to expect during each stage. Knowing the early pregnancy signs and tracking what’s normal gives you peace of mind and helps you bond with your growing baby.

Let’s walk through pregnancy, one week at a time—because every week matters on this beautiful journey from bump to baby.

1: Weeks 1–2 – The Countdown Begins

Pregnancy technically starts on the first day of your last menstrual period. You’re not technically pregnant yet, but your body is preparing to release an egg and create the perfect environment for conception.

Key changes:

• Ovulation typically happens around week 2
• You might feel slight cramping or see changes in cervical mucus
• Hormones begin shifting to support fertilization

Tracking ovulation is vital if you're trying to conceive. These early weeks lay the groundwork for everything to come.

2: Week 3 – Conception Happens

This is the magic moment. The sperm meets the egg, and fertilization occurs. The fertilized egg (now called a zygote) begins its journey down the fallopian tube toward the uterus.

What to expect:

• You won't feel any symptoms yet
• The zygote starts dividing rapidly
• Implantation is just days away

This marks the true start of your pregnancy—even if you don’t know it yet.

3: Week 4 – Implantation & Early Pregnancy Signs

The embryo implants into the uterus lining. This is when early pregnancy signs may begin to appear, though they’re often mild.

You might notice:

• Light spotting (implantation bleeding)
• Mild cramping
• Breast tenderness
• Fatigue

This is also the week a pregnancy test might show a positive result.

4: Week 5 – The Big Reveal

Your pregnancy hormone levels (hCG) are rising fast now. Many people confirm their pregnancy at this stage.

Pregnancy symptoms kick in:

• Morning sickness
• Sore breasts
• Mood swings
• Increased urination

The embryo is the size of a sesame seed and starting to form the brain and spinal cord.

5: Week 6 – Tiny Heartbeat

The baby’s heart begins to beat! It’s now visible on an ultrasound.

Common experiences:

• Nausea intensifies
• Food aversions or cravings
• Emotional ups and downs

The embryo is about 1/4 inch long and developing key organs.

6: Week 7 – Growing Fast

Your uterus is expanding, even if your belly isn’t showing. The baby is growing limbs and facial features.

Expect:

• Increased fatigue
• Darkening of the nipples
• Constipation or bloating

Your baby now looks more like a tiny human and is about the size of a blueberry.

7: Week 8 – Hello, Baby Bump?

You may notice slight weight gain or a tiny bump starting. The embryo is now officially called a fetus.

Pregnancy guide tips:

• Start prenatal vitamins
• Book your first prenatal visit
• Focus on hydration and nutrition

Your baby is now developing fingers, toes, and even taste buds.

8: Week 9 – Stronger Symptoms

Pregnancy symptoms may peak this week.

What you might feel:

• Headaches
• Frequent bathroom trips
• Heightened sense of smell

The baby’s heartbeat can often be detected by Doppler now. They’re about the size of a grape.

9: Week 10 – First Trimester Milestone

You’re nearly done with the first trimester. The risk of miscarriage drops, and many people breathe easier.

Expect:

• Slight weight gain
• Round ligament pain
• Ongoing nausea

Baby is developing teeth and organs. They’re the size of a kumquat.

10: Week 11 – Baby Starts Moving

Your baby is wiggling inside—though you won’t feel it yet.

Body changes include:

• Clearer skin or acne
• Thicker hair
• Increased vaginal discharge (normal)

Your little one is about 2 inches long and already kicking.

11: Week 12 – You Made It!

The end of the first trimester! You might start telling close friends and family.

Symptoms may ease:

• Less morning sickness
• More energy returns
• Belly begins to firm up

Your baby’s face is forming clearly, and their organs are fully functional.

12: Week 13 – Second Trimester Starts

Welcome to the "honeymoon phase" of pregnancy.

Common changes:

• Decreased nausea
• Growing bump
• Better sleep

Your baby can now swallow and is about 3 inches long.

13: Week 14–16 – Belly & Bonding

You’re likely feeling better and more connected to your pregnancy.

Things to do:

• Schedule anatomy scan
• Consider prenatal exercise
• Start shopping for maternity wear

By week 16, you might even feel the first tiny flutters of movement.

14: Week 17–20 – Halfway There

The halfway mark is here! Your baby is growing fast and starting to hear your voice.

Symptoms may include:

• Backaches
• Leg cramps
• Skin changes (linea nigra, stretch marks)

By week 20, you’ll have the anatomy scan to check development. It’s also when many find out the baby’s sex.

15: Week 21–24 – Movement Magic

You can now feel strong baby kicks, rolls, and jabs. This is an exciting time!

What to expect during pregnancy now:

• Shortness of breath
• Swollen ankles
• Braxton Hicks contractions (mild and irregular)

Your baby is growing fat stores and responding to light and sound.

16: Week 25–28 – Third Trimester Ahead

You’re wrapping up the second trimester and preparing for the final stretch.

New changes:

• Heartburn
• Difficulty sleeping
• Colostrum production (early breast milk)

Your baby is the size of an eggplant and practicing breathing movements.

17: Week 29–32 – Baby’s Gaining Weight

Your baby is getting chubby, and your body is preparing for birth.

You might notice:

• More frequent bathroom visits
• Swollen feet
• Stronger Braxton Hicks

This is a good time to take birthing classes and prep your hospital bag.

18: Week 33–36 – The Countdown Is On

It’s getting real. Your baby is settling into a head-down position.

Be ready for:

• Nesting instincts
• Disrupted sleep
• More pelvic pressure

Make sure you know the signs of labor and have your birth plan in place.

19: Week 37–40 – Full-Term & Ready

Any day now! Full-term begins at 37 weeks. Your baby is fully developed and ready to meet you.

Final symptoms:

• Loss of mucus plug
• Increased contractions
• “Lightening” as the baby drops

Stay hydrated, rest when you can, and keep in close contact with your healthcare provider.

Signs of Labor

How do you know labor is near? Here's a quick checklist:

• Strong, regular contractions
• Water breaking
• Lower back pain that comes and goes
• Bloody show (mucus tinged with blood)
• Sudden burst of energy or nesting

When in doubt, call your doctor or go to the hospital. Trust your instincts.

Conclusion

Pregnancy is a journey of transformation, wonder, and love. This pregnancy week-by-week guide is your companion through every heartbeat, every flutter, and every milestone. By understanding what to expect during pregnancy, recognizing early pregnancy signs, and tracking your symptoms, you stay empowered and prepared.

From the quiet early days to the triumphant moment of birth, every week is worth celebrating.