Week by Week Pregnancy Guide
Follow your baby's amazing development from the earliest days of pregnancy through birth. This guide covers what's happening with your baby and your body each week.
Three Trimesters at a Glance
Baby's Development
Your body is preparing for ovulation. Pregnancy is dated from the first day of your last period, even though conception hasn't occurred yet.
What You May Experience
Your menstrual period occurs and your body prepares to release an egg.
Baby's Development
Fertilization occurs! The fertilized egg (zygote) begins dividing as it travels down the fallopian tube.
What You May Experience
You may not know you're pregnant yet. The fertilized egg is implanting in your uterine lining.
Baby's Development
The blastocyst implants in the uterus. The placenta begins to form. The embryo has two layers of cells.
What You May Experience
You may miss your period. Some women experience implantation bleeding or cramping.
Baby's Development
The neural tube (which becomes the brain and spinal cord) is forming. The heart begins to beat.
What You May Experience
Morning sickness may begin. Breast tenderness and fatigue are common.
Baby's Development
Facial features begin forming. The heart is beating about 150 times per minute. Arm and leg buds appear.
What You May Experience
Nausea, frequent urination, and mood swings may be intensifying.
Baby's Development
The brain is growing rapidly. Hands and feet are forming. The embryo is about 1 cm long.
What You May Experience
Food aversions and cravings may develop. Excess saliva is common.
Baby's Development
Fingers and toes are forming. All major organs have begun developing. The embryo begins to move.
What You May Experience
Your uterus is about the size of a large orange. Nausea may peak around this time.
Baby's Development
The embryo officially becomes a fetus. Muscles are forming and the baby can make tiny movements.
What You May Experience
Weight gain typically begins. Your waistline may start thickening.
Baby's Development
All vital organs are formed and beginning to function. Fingers and toes are no longer webbed.
What You May Experience
Visible veins may appear due to increased blood volume. Ligament pain may begin.
Baby's Development
The baby can open and close its fists. Tooth buds are forming under the gums. External genitalia begin developing.
What You May Experience
Nausea may start to improve. You may feel warmer due to increased blood volume.
Baby's Development
The baby is about 2.5 inches long. Reflexes are developing — the baby can squint and open its mouth.
What You May Experience
The risk of miscarriage drops significantly. Many parents share their news at this point.
Baby's Development
The baby can suck its thumb. Vocal cords are developing. The intestines move from the umbilical cord into the abdomen.
What You May Experience
Welcome to the second trimester! Energy levels often improve.
Baby's Development
The baby's facial features become more defined. Hair begins growing. The baby can make facial expressions and may begin hearing sounds.
What You May Experience
The 'pregnancy glow' often appears. You may feel the first flutters of movement (quickening).
Baby's Development
The anatomy scan typically happens during this period. The baby's sex can be determined. Vernix (waxy coating) covers the skin. The baby is developing a sleep-wake cycle.
What You May Experience
Most mothers feel definite fetal movement. Your belly is clearly showing. The anatomy ultrasound checks baby's development.
Baby's Development
The baby's lungs are developing surfactant. Eyes can open. The baby responds to light and sound. Rapid brain development occurs.
What You May Experience
Glucose screening test (24-28 weeks). Back pain and Braxton Hicks contractions may occur. The top of your uterus is above your belly button.
Baby's Development
The baby can blink, dream (REM sleep), and regulate body temperature. Bones are hardening. The baby is gaining weight rapidly.
What You May Experience
Welcome to the third trimester! More frequent prenatal visits begin. Shortness of breath and heartburn are common.
Baby's Development
The baby is practicing breathing movements. Bones are fully formed but still soft. The baby moves into head-down position (usually).
What You May Experience
GBS test (35-37 weeks). Nesting instincts may kick in. Braxton Hicks may increase.
Baby's Development
The baby is considered early term at 37 weeks. Lungs are nearly mature. The baby drops lower into the pelvis (lightening).
What You May Experience
You may breathe easier as baby drops but feel more pelvic pressure. Pack your hospital bag!
Baby's Development
The baby is full term. Average weight is 6-9 pounds. The baby is ready for life outside the womb.
What You May Experience
Watch for signs of labor: regular contractions, water breaking, bloody show. Your due date is at 40 weeks!
Track your pregnancy week by week
Find Out How Many Weeks You AreMedical Disclaimer
This guide is for informational purposes only. Every pregnancy is unique. Always consult your healthcare provider for personalized medical advice.