Your baby is conceived
June 05, 2026
Baby's Size This Week
Week 4
Poppy seed
Your baby is about the size of a poppy seed this week
Pregnancy Achievements
Heartbeat Hero
Week 6 - Heart starts beating
Tiny Human
Week 10 - All organs formed
1st Trimester Champion
Week 13 - First trimester complete
Halfway There!
Week 20 - 50% complete
Viability Victory
Week 24 - Baby could survive outside womb
Dream Weaver
Week 28 - REM sleep & dreaming begins
Significant Milestones in Embryo/Fetal Development
✨
Week 2
🧪
Positive pregnancy test
June 19, 2026 - You are here
Week 4
❤️
Organs begin to form, heart starts beating
June 26, 2026
Week 5
🩺
Major organs have formed, heart can be heard
July 31, 2026
Week 10
🛡️
Second trimester, risk of miscarriage decreases
August 14, 2026
Week 12
📢
Now is a good time to announce your pregnancy
August 28, 2026
Week 14
👁️
Your baby can now see light
September 04, 2026
Week 15
🔍
Your baby's gender is visible on ultrasound
September 11, 2026
Week 16
🤰
You can feel your baby move around
September 25, 2026
Week 18
👂
Your baby can now hear sounds
October 02, 2026
Week 19
🏥
Premature babies have a chance to survive
October 30, 2026
Week 23
🌬️
Third trimester, your baby can breathe
November 27, 2026
Week 27
💅
Fingernails and toenails have formed
January 01, 2027
Week 32
✅
Your baby is now considered full term
February 05, 2027
Week 37
🎉
Your baby is due any time now!
February 26, 2027
Week 40
Weekly Development Progress
Your baby may not look particularly different this week, still appearing as a tiny ball of cells, about 1mm in diameter; that's smaller than a poppy seed. However, there's been some big changes in the last 7 days as the cell cluster continues to divide rapidly. Soon, these cells will begin to organize into three distinct layers (called germ layers) that will eventually form all of your baby's organs and tissues.
The cell cluster itself will complete the implantation process during week 4, which is the attachment of the fertilized egg into the walls of the uterus. The high levels of estrogen and progesterone in your body at this time keep the wall lining thick and healthy, which is essential not only for holding on tightly to the cells and keeping them safe, but also for providing nutrients as the placenta isn't quite ready for this task just yet (but it's been working overtime and will be very soon!)
Video & Ultrasound Pictures
Video
Development Week 4 Video
What Your Baby Can Hear
Your baby's ears are still developing. At week 4, the inner ear structures are forming. Baby will begin hearing around week 18.
Hearing Development Timeline
Week 6
Inner ear begins forming
The cochlea and vestibular system start developing from the otic placode.
Week 16
Ears reach final shape
The outer ears are now fully formed and in their correct position on the head.
Week 18
First sounds detected
Baby begins to hear internal sounds: your heartbeat, blood flow, and digestive system.
Week 22
Responds to voices
Baby can hear your voice and may respond to it with movement. They prefer low-pitched sounds.
Week 25
Reacts to music
Baby can hear music and external sounds. Studies show babies prefer classical and soft music.
Week 27
Startles at loud noise
The auditory system is mature enough to startle at sudden loud sounds.
Week 32
Recognizes your voice
Baby can distinguish your voice from others and shows a preference for it after birth.
Week 35
Remembers music
Research shows babies can remember and recognize melodies heard in the womb after birth.
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