Follow your baby's development and get essential tips for every week of your journey.
Clinical Dating Context: Pregnancy weeks are conventionally calculated from the first day of your last menstrual period (LMP).
Calendar calculations are educational estimates; individual conception timing and gestational development vary. Ultrasound and clinical evaluation by a healthcare provider remain the standard for precise dating and medical care.
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This Week-by-Week Pregnancy Calendar is an educational guide outlining the typical stages of fetal development, maternal body changes, and practical milestones across all 40 weeks of gestation.
If you need to determine exactly how far along you are today based on your dates, use our dedicated Pregnancy Week Calculator. While that tool estimates your current gestational age in weeks and days, this calendar provides detailed weekly reference information about fetal growth, anatomical development, and common symptoms.
Individual pregnancies vary naturally. Biological averages provide a helpful guide, but ultrasound dating and personalized clinical guidance from your healthcare provider remain the standard for medical care.
Week 1 Pregnancy: Baby Development, Symptoms & Tips
Body prepares for ovulation
Menstrual bleeding, cramps
Track cycle, start folic acid
Week 2 Pregnancy: Baby Development, Symptoms & Tips
Ovulation occurs
Increased cervical mucus
Plan intercourse during fertile window
Week 3 Pregnancy: Baby Development, Symptoms & Tips
Fertilization and early cell division commonly occur around this stage
Mild cramping, spotting
Avoid alcohol and smoking
Week 4 Pregnancy: Baby Development, Symptoms & Tips
Implantation commonly occurs around this time
Missed period, light spotting
Take pregnancy test
Week 5 Pregnancy: Baby Development, Symptoms & Tips
Heart begins forming
Nausea, fatigue
Eat small frequent meals
Week 6 Pregnancy: Baby Development, Symptoms & Tips
Heartbeat may begin
Morning sickness, breast tenderness
Stay hydrated
Week 7 Pregnancy: Baby Development, Symptoms & Tips
Brain and face developing
Fatigue, nausea
Get enough rest
Week 8 Pregnancy: Baby Development, Symptoms & Tips
Limbs forming, brain growth
Nausea, mood swings
Maintain healthy diet
Week 9 Pregnancy: Baby Development, Symptoms & Tips
Facial features forming
Bloating, fatigue
Continue prenatal vitamins
Week 10 Pregnancy: Baby Development, Symptoms & Tips
Organs forming
Nausea, dizziness
Avoid raw foods
Week 11 Pregnancy: Baby Development, Symptoms & Tips
Bones hardening
Fatigue reducing
Stay active
Week 12 Pregnancy: Baby Development, Symptoms & Tips
Reflexes developing
Less nausea
Schedule checkup
Week 13 Pregnancy: Baby Development, Symptoms & Tips
Vocal cords forming
Energy returns
Start light exercise
Week 14 Pregnancy: Baby Development, Symptoms & Tips
Facial expressions begin
Reduced nausea
Eat balanced diet
Week 15 Pregnancy: Baby Development, Symptoms & Tips
Skeleton developing
Mild aches
Calcium intake
Week 16 Pregnancy: Baby Development, Symptoms & Tips
Muscle movement
Possible baby movement
Stay hydrated
Week 17 Pregnancy: Baby Development, Symptoms & Tips
Fat layer forming
Increased appetite
Healthy snacks
Week 18 Pregnancy: Baby Development, Symptoms & Tips
Hearing develops
Baby kicks
Talk to baby
Week 19 Pregnancy: Baby Development, Symptoms & Tips
Sensory development
Skin changes
Moisturize skin
Week 20 Pregnancy: Baby Development, Symptoms & Tips
Midpoint milestone for a 40-week pregnancy
Visible bump
Anatomy scan
Week 21 Pregnancy: Baby Development, Symptoms & Tips
Digestive system developing
Stretch marks
Stay hydrated
Week 22 Pregnancy: Baby Development, Symptoms & Tips
Eyes forming
Back pain
Posture care
Week 23 Pregnancy: Baby Development, Symptoms & Tips
Lungs developing
Swelling
Elevate feet
Week 24 Pregnancy: Baby Development, Symptoms & Tips
Hearing strong
Braxton Hicks
Hydration
Week 25 Pregnancy: Baby Development, Symptoms & Tips
Brain growth
Sleep issues
Side sleeping
Week 26 Pregnancy: Baby Development, Symptoms & Tips
Eyes open
Leg cramps
Stretching
Week 27 Pregnancy: Baby Development, Symptoms & Tips
Rapid brain growth
Heartburn
Small meals
Week 28 Pregnancy: Baby Development, Symptoms & Tips
Nervous system develops
Shortness of breath
Rest often
Week 29 Pregnancy: Baby Development, Symptoms & Tips
Muscle growth
Fatigue
Iron-rich foods
Week 30 Pregnancy: Baby Development, Symptoms & Tips
Fat accumulation
Back pain
Support belt
Week 31 Pregnancy: Baby Development, Symptoms & Tips
Brain connections increase
Frequent urination
Stay hydrated
Week 32 Pregnancy: Baby Development, Symptoms & Tips
Bones fully formed
Braxton Hicks
Relaxation
Week 33 Pregnancy: Baby Development, Symptoms & Tips
Immune system develops
Swelling
Follow balanced pregnancy nutrition guidance and individualized advice from your healthcare provider
Week 34 Pregnancy: Baby Development, Symptoms & Tips
Lungs maturing
Pelvic pressure
Rest
Week 35 Pregnancy: Baby Development, Symptoms & Tips
Weight gain increases
Fatigue
Prepare hospital bag
Week 36 Pregnancy: Baby Development, Symptoms & Tips
Baby drops lower
Breathing easier
Watch for labor signs
Week 37 Pregnancy: Baby Development, Symptoms & Tips
Early term begins (full term is 39–40 weeks)
Contractions
Stay ready
Week 38 Pregnancy: Baby Development, Symptoms & Tips
Organs ready
Pelvic pain
Rest
Week 39 Pregnancy: Baby Development, Symptoms & Tips
Ready for birth
Strong contractions
Contact doctor if labor starts
Week 40 Pregnancy: Baby Development, Symptoms & Tips
Fully developed
Labor signs
Delivery expected
Our week-by-week pregnancy calendar is designed to be your companion from the moment you decide to conceive until you meet your little one. You can track baby development by week, identify which pregnancy symptoms by week are normal, and prepare for the pregnancy stages week by week.
While the first two weeks of the pregnancy growth chart week by week are technically before conception, by what happens at 8 weeks pregnant, your baby already has a heartbeat and developing organs. This fetal development timeline provides the essential milestones for every stage.
Support your journey from pre-conception through delivery with our comprehensive suite of fertility and pregnancy tools:
Estimate your exact current week and days of pregnancy based on your last period or due date.
Calculate your estimated delivery date using your LMP, conception date, or IVF transfer timing.
Identify your expected embryo implantation window and optimal pregnancy test dates.
Track daily symptoms and test accuracy milestones days past ovulation.
Explore additional calendar views and timeline estimates among our pregnancy dating and calendar tools.
Pregnancy is standardly measured from the first day of your last menstrual period (LMP), which typically precedes ovulation and fertilization by about two weeks. Because precise conception timing can vary, healthcare providers rely on LMP as a standardized clinical baseline, dividing the estimated 40-week gestation into three trimesters.
Biological development begins at conception when a sperm fertilizes an egg, typically occurring around week 3 of an LMP-based calendar. The resulting zygote undergoes rapid cell division as it travels toward the uterus to implant, initiating embryonic organ and structural formation.
Every week of pregnancy plays an essential role in fetal development. The first trimester (weeks 1–13) is critical for foundational organogenesis and body system formation, while the second and third trimesters support essential brain growth, lung maturation, and weight gain leading up to delivery.
Most expecting mothers begin to detect fetal movement (quickening) between weeks 16 and 25. Women in their second or subsequent pregnancies often recognize these flutter-like movements earlier than first-time mothers, and placental position (such as an anterior placenta) can also influence when movement is felt.
A week-by-week pregnancy calendar provides general educational milestones based on standard biological averages. Because menstrual cycle lengths, ovulation timing, and individual fetal growth rates vary naturally, clinical evaluation and ultrasound dating by a qualified healthcare provider remain the medical standard for pregnancy management.