Tracking your pregnancy week by week helps you understand the amazing transformation taking place inside your body and follow every milestone of your baby’s development. From the initial cellular division to the clear formation of organs and limbs, knowing what to expect at each stage brings clarity and peace of mind. We’ve broken it down into 3 trimesters; see below for the details:
First Trimester of Pregnancy
Follow your baby’s development week by week (Weeks 2 to 13)
Ovulation occurs about two weeks after your last period. If egg meets sperm, fertilization takes place and your pregnancy journey begins.
Your baby is a microscopic ball of several hundred cells called a blastocyst, rapidly multiplying as it travels down the fallopian tube.
The blastocyst implants in your uterine wall. It splits into the embryo and the primitive placenta, which will nourish your baby.
The tiny embryo is growing rapidly. The neural tube, which eventually becomes the brain and spinal cord, begins to form.
Your baby’s heart begins to beat! Facial features like nose, mouth, and eyes are starting to take shape along with tiny limb buds.
Baby has generated 100 new brain cells every minute! Hands and feet are emerging from the arm and leg buds.
Tiny fingers and toes are forming. The embryonic tail is nearly gone, and baby is making small, spontaneous movements.
Essential organs like the heart, brain, kidneys, and liver are developing quickly as your baby transitions out of the embryonic stage.
Baby is officially a fetus! Bones and cartilage are forming, and tiny tooth buds are appearing under the gums.
Your baby is almost fully formed. They are kicking, stretching, and even hiccuping as their diaphragm develops.
Most critical systems are formed! Reflexes kick in—baby’s fingers will soon begin to open and close, and toes will curl.
The final week of the first trimester! Fingerprints have formed, and vocal cords are beginning to develop.
Second Trimester of Pregnancy
Follow your baby’s growth and belly bump transformation (Weeks 14 to 27)
Your baby is making facial expressions with tiny features. You may feel more energetic and less nauseated as energy returns.
Baby can now move joints and form taste buds. A stuffy nose might pop up—a surprising side effect of increased blood flow.
Your baby is heading into a major growth spurt. Eyes are slowly becoming responsive to light, and tiny fingernails are growing.
Soft cartilage is hardening into bone, and the umbilical cord is growing thicker and stronger to supply needed nutrients.
Baby is flexing arms and legs! You might feel early fluttery movements called quickening during this week or very soon.
A protective coating called vernix caseosa forms on baby’s skin to shield it from amniotic fluid.
Halfway there! Your baby is swallowing more amniotic fluid, which is great practice for their digestive system.
Baby’s movements are becoming more distinct. Eyebrows and eyelids are fully present now.
Lips and mouth are becoming more defined, and baby’s sense of sight is developing as they perceive light and shadow outside the womb.
Baby can hear your voice and heartbeat clearly! Rapid eye movements (REM) begin, showing early dream cycles.
Baby is gaining fat and filling out. Their inner ear is fully developed, helping them understand balance and orientation.
Baby is growing hair with color and texture. Capillaries are forming to supply oxygenated blood throughout the body.
Baby’s eyes are opening for the first time! Inhaling and exhaled movements are practicing lung function for birth.
The final week of the second trimester! Brain tissue is developing rapidly, and baby now sleeps and wakes at regular intervals.
Third Trimester of Pregnancy
Follow your baby’s final growth and readiness for birth (Weeks 28 to 41)
Welcome to the third trimester! Baby can dream, blink, and turn their head toward bright light outside the belly.
Baby is putting on weight fast. Their muscles and lungs continue to mature as bone structure strengthens.
Red blood cells are now being produced by the bone marrow. Amniotic fluid volume peaks around this week.
Major brain connection developments are happening. Baby can process information from all five senses.
Toenails and fingernails are fully formed. Baby is practicing breathing motions to prepare for life outside.
Antibodies are passing from mom to baby to build their immune system. Bones are fully developed but soft and pliable.
Fat layers are filling out baby’s skin, making it smooth and pink. Central nervous system is continuing to mature.
Kidneys are fully developed, and the liver can process some waste products. The womb is getting cozy and snug!
Baby is likely shifting into a head-down position for birth. Lungs are nearly ready for their very first breath.
You’ve reached early term! Baby’s grasp is firm, and organs are ready to function on their own.
Lanugo (downy hair) and vernix coating are shedding into amniotic fluid. Vocal cords are ready for that first cry.
Full term! Baby’s brain continues to grow rapidly. They are fully formed and ready to meet you anytime.
Your official due date is here! Skull bones remain soft to allow easy passage through the birth canal during labor.
Late term! Baby is extra plump and cozy. Your doctor will monitor closely to ensure baby stays healthy until delivery.
Also Check: Pregnancy Due Date Calculator