Pregnancy Week by Week: Complete Fetal Development and Milestones Guide

Pregnancy is one of the most transformative experiences a woman will ever undergo. From the moment you see that positive test, a tiny life begins growing inside you, and every single week brings new changes, both for your baby and your body. Pregnancy Week by Week!

This week-by-week pregnancy guide is your companion through each stage of fetal development, helping you understand what’s happening and why. Whether you’re newly expecting or deep into your second trimester of pregnancy, this guide provides you with the knowledge, support, and reassurance you need.

Let’s explore the beautiful journey from conception to birth, from the due date to the last trimester.

Pregnancy Milestones Week by Week 

First Trimester (Weeks 1–13): The Foundation of Life

Weeks 1–4: Conception & Implantation (Early pregnancy)
Pregnancy begins before you even know it. The first two weeks are calculated from your last menstrual period. By the third week or week 4, fertilisation occurs, and the embryo implants into the uterus. You may start to notice early signs, such as fatigue, bloating, or breast tenderness.

Week 5: Positive Pregnancy Test
The fifth week is the week when most women get that life-changing positive test result. The embryo is growing rapidly, and the neural tube (brain and spinal cord) starts forming.

Weeks 6–8: Major Organs Begin to Develop
Your baby’s heart begins to beat! Facial features form, and tiny limb buds appear. Morning sickness may kick in around this time, thanks to rising hCG levels. (week 6, week 7 & week 8)

Weeks 9–13: First Glimpses of Baby
By week 12 (12 weeks), your baby begins to look more human, with fingers and toes becoming visible. Ultrasounds may show the baby moving around, even though you can’t feel it yet. Your uterus is growing, and hormones continue to shift, bringing symptoms like cravings or mood swings. Your baby is growing, and many changes are happening. (week 9, week 10, week 11, week 12 and week 13)

Second Trimester (Weeks 14–27): The Golden Period – Pregnancy Milestones Week by Week

Weeks 14 – 16: Energy Returns
You might start to feel more energised as nausea fades. This is a great time to focus on healthy eating and light exercise. Your baby’s gender may now be visible via ultrasound.

Weeks 17–20: Baby’s Movements Begin
Many mums begin to feel the first flutters—called “quickening”—especially if this isn’t their first baby. Your uterus is rising, and your bump may now be noticeable.

Week 20: Halfway There
At the mid-pregnancy anatomy scan, doctors check your baby’s organs, growth, and position. The baby now weighs approximately 300g, and its hearing and swallowing functions are developing.

Weeks 21–24: More Growth & Kicks
You may feel stronger kicks and see belly movements. The baby is gaining weight, and eyebrows, eyelashes, and taste buds are developing. (week 24)

Weeks 25–27: Preparing for Life Outside
Your baby’s lungs and brain are maturing. Fat is starting to develop under the skin. You may notice more Braxton Hicks contractions as your body prepares for labour.

Third Trimester (Weeks 28–40+): The Final Stretch

Weeks 28–32: Baby’s Eyes Open
Baby can now blink and respond to light and sound. Their body is filling out, and you may start noticing patterns in sleep and movement.

Week 33– Week 36: Get Ready for Birth
Your baby is practicing breathing, sucking, and swallowing. The head may begin to move downward into the pelvis. It’s time to prepare your hospital bag and birth plan.

Weeks 37–40: Full-Term Baby (40 Weeks)
You’ve made it! Any time now, your baby could arrive. At full term, the baby typically weighs approximately 3–4 kg and measures around 50 cm in length. You may feel anxious, excited, or both—and that’s completely normal.

Common Pregnancy Questions Answered – Pregnancy Week by Week

When should I see my doctor?
As soon as you get a positive test result. Early care plays a crucial role in ensuring a healthy pregnancy.

Is it normal to feel overwhelmed?
Absolutely. Your body, hormones, and life are all changing. Don’t hesitate to reach out for support.

What if I’m not feeling connected to my baby yet?
That’s okay. Bonding takes time. Use your week-by-week milestones to build a connection by talking to your baby or journaling your journey.

Why Tracking Pregnancy Week by Week Milestones Matters

Understanding each stage of fetal development helps you feel confident and informed. When you know what to expect, you’re more prepared to make the best choices for your health and your baby’s growth.

Tracking also helps you:

• Notice early warning signs
• Bond with your growing baby
• Feel reassured through every stage
• Plan for upcoming tests and scans
• Communicate better with your care provider

Grab Your eBook Guide Today

Our beautifully designed Pregnancy Milestones Week by Week eBook includes:

• Clear weekly breakdowns from conception to delivery
• Fetal development insights
• Real-mum tips and emotional support
• Expert-approved advice for every trimester

Whether it’s your first baby or your third, this guide makes the journey easier and more joyful.

👉 Grab your eBook Guide today.
👉 Join the Parenting Genie Community for more expert tips, support, and weekly pregnancy resources. 2 Weeks Free Trial.

Final Thoughts – Pregnancy Milestones Week by Week

Pregnancy is not just about growing a baby; it’s about growing into a new version of yourself. Every flutter, every ultrasound, every symptom is part of the story. With Parenting Genie by your side, you’re never alone.

Track your milestones, feel supported, and step into motherhood with confidence and empowerment.

The Raising Children website offers valuable tips and insights from pregnancy to raising children.