Week 6 of Pregnancy
Learn about your baby's development and what to expect at 6 weeks pregnant.
Baby's Size This Week
Baby Development at Week 6
- ● Your embryo is approximately 4-6 mm long, and the heartbeat may now be visible on a transvaginal ultrasound.
- ● The heart is developing four chambers and beating at about 100-160 beats per minute.
- ● Tiny dark spots mark where the eyes will be, and small depressions indicate the future ear canals and nostrils.
- ● The neural tube is closing, and the brain is rapidly differentiating into three main sections: forebrain, midbrain, and hindbrain.
- ● Arm and leg buds are growing longer, and paddle-like hands are beginning to form at the ends of the arm buds.
- ● The intestines and lungs are beginning to develop from the endoderm layer, alongside the liver and pancreatic buds.
Your Body at Week 6
- ● Morning sickness may intensify this week, with nausea occurring at any time of day or night.
- ● Breast changes continue — veins may become more visible and areolas may begin to darken.
- ● Fatigue remains significant as your body produces up to 50% more blood to support the growing embryo.
- ● Bloating and gas are common due to progesterone slowing your digestive system (gastric motility decreases).
- ● You may notice more frequent urination as the growing uterus presses on your bladder.
- ● Saliva production may increase (ptyalism), which is more common in women experiencing severe nausea.
Week 6 Checklist
- ☐ If nausea is severe, ask your provider about safe anti-nausea medications like vitamin B6 or doxylamine.
- ☐ Eat small, frequent meals and keep crackers by your bedside to combat morning nausea before getting up.
- ☐ Continue taking your prenatal vitamin — try taking it at night with food if it causes daytime nausea.
- ☐ Stay active with gentle walks or light stretching to help with fatigue and mood.
- ☐ Begin thinking about when and how you want to share your pregnancy news with family and friends.
- ☐ Research your health insurance coverage for prenatal care, genetic testing, and delivery costs.
Frequently Asked Questions
When can I hear my baby's heartbeat?
A heartbeat may be visible on a transvaginal ultrasound as early as 6 weeks, though 7-8 weeks is more common. Using a Doppler device at prenatal appointments, you can typically hear the heartbeat between 10-12 weeks. The heart rate at 6 weeks is usually 100-120 bpm and will increase to 150-170 bpm by week 9.
Is spotting normal at 6 weeks pregnant?
Light spotting can be normal in early pregnancy and occurs in about 20-30% of pregnancies. It may be caused by cervical irritation, implantation bleeding, or normal uterine changes. However, contact your healthcare provider if bleeding is heavy, bright red, accompanied by severe cramping, or if you experience dizziness, as these could signal a miscarriage or ectopic pregnancy.
What if I don't see a heartbeat at my 6-week ultrasound?
Not seeing a heartbeat at exactly 6 weeks is not uncommon, especially if your dates are slightly off. Many providers will schedule a follow-up ultrasound 1-2 weeks later to recheck. A heartbeat is typically expected by 7-8 weeks. If no heartbeat is detected at the follow-up, your provider will discuss next steps.
Can morning sickness harm my baby?
Normal morning sickness does not harm your baby. Your baby draws nutrients from your reserves even when you cannot eat much. However, severe nausea and vomiting (hyperemesis gravidarum) that prevents you from keeping any food or fluids down, causes weight loss, or leads to dehydration requires medical treatment. Contact your provider if you cannot keep liquids down for 24 hours.
What is hyperemesis gravidarum and when should I seek help?
Hyperemesis gravidarum (HG) is a severe form of pregnancy nausea affecting about 1-3% of pregnant women. Unlike typical morning sickness, HG involves vomiting more than 3-4 times per day, losing more than 5% of pre-pregnancy body weight, and being unable to keep food or fluids down. Signs requiring medical attention include dark urine, dizziness, fainting, and inability to eat for 24+ hours. IV fluids and prescription anti-nausea medications are available treatments.
Track Your Exact Pregnancy Week
Use our free Pregnancy Week Tracker to find out exactly how far along you are based on your last menstrual period or due date.
Track My Pregnancy →Sources
- ACOG
- WHO Fetal Growth Charts
- Mayo Clinic
Medical disclaimer: This content is for informational purposes only and is not intended as medical advice. Always consult a qualified healthcare provider for guidance specific to your pregnancy.