Week 6 of pregnancy
Updated 8 Nov 2026
Your baby this week
About the size of a mung bean
Source: Vinmec – Bảng cân nặng và chiều dài thai nhi theo tiêu chuẩn của WHO
Your baby's development
Your baby is now the size of a bean.
Your baby is the size of a small bean, about 0.5 - 0.6 cm. At this point your baby still has the shape of an embryo, like a tadpole with a slightly large head. There are folds that will later form the face, such as the ears, nose and mouth.
Little buds of arms and legs are starting to grow. Internal organs such as the heart, blood vessels and nerves are developing rapidly. Along with them come the beginnings of the lungs, digestive system, cardiovascular system, urinary system...The placenta also keeps building up to gradually replace the yolk sac.
Fetal heartbeat:
You may be able to hear your baby's heartbeat with a transvaginal ultrasound.
Your body
More morning sickness:
In week 6 of pregnancy your morning sickness will start to get worse, and your mood may swing because of changing progesterone levels in your blood. You will often feel nauseous, bloated, and have acid reflux and heartburn. Together with changes in the hormone HCG, this makes you need to pee more often. These symptoms will gradually ease by the end of the first 3 months of pregnancy, so hang in there.
Advice for you
When you pee, lean forward to empty your bladder completely. But don't cut down on water, because your body always needs a steady supply of fluids.
Signs that need a doctor now
If you notice any of the signs below, please go to the nearest health facility to be checked by a doctor.
Vaginal bleeding in pregnancy
This sign needs to be checked by a doctor. Please go to the nearest health facility now. If the bleeding is heavy or comes with severe pain or faintness, call the emergency number 115.
Source: Bệnh viện Đa khoa Tâm Anh – Các dấu hiệu nguy hiểm trong thai kỳ
Convulsions (fits)
A convulsion in pregnancy is an emergency. Family members should call 115 at once, lay the mother on her side in a safe place and get her to the nearest hospital.
Source: Bệnh viện Đa khoa Tâm Anh – Các dấu hiệu nguy hiểm trong thai kỳ
Fever in pregnancy
A temperature above 38°C counts as a fever. Please go to a health facility so a doctor can find the cause and advise on safe ways to bring it down; do not take medicine on your own.
Source: Bệnh viện Đa khoa Tâm Anh – Các dấu hiệu nguy hiểm trong thai kỳ
Leaking fluid or waters breaking
Fluid leaking from the vagina may mean the waters are leaking or have broken and needs to be checked by a doctor. Please go to a health facility soon, lying with your head low while travelling.
Source: Bệnh viện Đa khoa Tâm Anh – Các dấu hiệu nguy hiểm trong thai kỳ
Severe headache, blurred vision, sudden swelling
Headache with blurred vision, or sudden swelling of the face, hands or eyelids, can be a sign of high blood pressure in pregnancy or pre-eclampsia. This sign needs to be checked by a doctor. Please go to the nearest health facility now.
Source: Bệnh viện Đa khoa Tâm Anh – Các dấu hiệu nguy hiểm trong thai kỳ
Reduced or no fetal movement
A clear drop in the baby's movements, or no movement, needs to be checked by a doctor. Please go to the nearest health facility now rather than waiting until tomorrow.
Source: Bệnh viện Đa khoa Tâm Anh – Các dấu hiệu nguy hiểm trong thai kỳ
Severe or worsening abdominal pain
Abdominal pain that keeps getting worse, does not ease, or is severe needs to be checked by a doctor. Please go to the nearest health facility now. If the pain is severe with sweating, faintness or bleeding, call 115.
Source: Bệnh viện Đa khoa Tâm Anh – Các dấu hiệu nguy hiểm trong thai kỳ
Sources
Content advised by our doctors.
- Vinmec – Sự phát triển của thai nhi tuần 6 (accessed 22 Oct 2026)
- Bệnh viện Từ Dũ – Lịch khám thai 3 tháng đầu (accessed 22 Oct 2026)
- NHS – 6 weeks pregnant guide (accessed 22 Oct 2026)
- Source for fetal size: Vinmec – Bảng cân nặng và chiều dài thai nhi theo tiêu chuẩn của WHO
- Source for the signs that need a doctor: Bệnh viện Đa khoa Tâm Anh – Các dấu hiệu nguy hiểm trong thai kỳ
This article helps you understand and prepare. It does not replace a check-up. For an answer about your own situation, please ask the doctor who is caring for you.