Pregnancy Week by Week: What to Expect

Pregnancy is an incredible journey spanning approximately 40 weeks, divided into three trimesters. Understanding what happens each week helps you prepare for the changes ahead and ensures the best care for you and your baby.

Understanding Pregnancy Trimesters

Pregnancy is divided into three trimesters:

• First Trimester: Weeks 1-13

• Second Trimester: Weeks 14-27

• Third Trimester: Weeks 28-40

First Trimester (Weeks 1-13)

Weeks 1-4: Conception and Early Development

What's Happening

• Fertilization occurs

• Embryo implants in uterine wall

• Pregnancy hormones start production

Your Body

• You may not realize you're pregnant yet

• Missed period is the first sign

• Light spotting possible during implantation

What to Do

• Take a pregnancy test if period is late

• Start prenatal vitamins with folic acid

• Avoid alcohol, smoking, and certain medications

Weeks 5-8: Rapid Growth

Baby's Development

• Heart begins to beat (around week 6)

• Neural tube develops (becomes brain and spine)

• Limb buds form

• Size: From poppy seed to raspberry

Your Symptoms

• Morning sickness may begin

• Fatigue and exhaustion

• Breast tenderness

• Frequent urination

• Mood swings

Care Tips

• Schedule first prenatal appointment

• Eat small, frequent meals for nausea

• Stay hydrated

• Get plenty of rest

Weeks 9-13: End of First Trimester

Baby's Development

• All major organs have formed

• Baby can make movements (not felt yet)

• Fingers and toes developing

• Size: From grape to lemon

Your Body

• Morning sickness may peak

• Clothes may feel tighter

• Energy levels may improve toward week 13

Important Milestones

• First ultrasound usually scheduled

• Nuchal translucency screening

• Blood tests for genetic conditions

• Hear baby's heartbeat

Second Trimester (Weeks 14-27)

Weeks 14-17: The "Golden Period"

Baby's Development

• Facial features becoming distinct

• Can hear sounds

• Making sucking motions

• Size: From peach to avocado

Your Experience

• Energy returns

• Morning sickness usually subsides

• Baby bump becomes visible

• Skin may glow

What's New

• May feel baby's first movements (quickening)

• Usually happens between weeks 16-20

• Second prenatal appointment

Weeks 18-22: Feeling Baby Move

Baby's Development

• Covered in vernix (protective coating)

• Developing sleep-wake cycles

• Can hear your voice

• Size: From bell pepper to banana

Your Body

• Round ligament pain common

• Backaches may begin

• Increased appetite

• Visible baby movements

Key Appointments

• Anatomy scan (around week 20)

• Can learn baby's gender

• Check for developmental abnormalities

Weeks 23-27: Growing Rapidly

Baby's Development

• Lungs developing but not mature

• Eyes can open

• Brain growing rapidly

• Size: From grapefruit to cauliflower

Your Changes

• Braxton Hicks contractions may start

• Possible swelling in hands and feet

• Possible heartburn

• More frequent bathroom trips

Testing

• Glucose screening test (weeks 24-28)

• Regular blood pressure checks

Third Trimester (Weeks 28-40)

Weeks 28-32: Preparation Phase

Baby's Development

• Can see, hear, taste, and touch

• Bones fully formed but still soft

• Gaining weight rapidly

• Size: From eggplant to coconut

Your Experience

• Shortness of breath

• More pronounced Braxton Hicks

• Difficulty sleeping

• Increased fatigue

Preparations

• Start childbirth classes

• Tour hospital or birth center

• Prepare nursery

• Discuss birth plan with doctor

Weeks 33-36: Almost There

Baby's Development

• Lungs nearly mature

• May drop lower into pelvis

• Gaining about 0.5 pounds per week

• Size: From pineapple to honeydew melon

Your Body

• Increased pelvic pressure

• More frequent urination

• Possible leaking of colostrum

• Increased fatigue

Medical Care

• Weekly prenatal visits begin

• Group B strep test (weeks 35-37)

• Monitoring baby's position

Weeks 37-40: Full Term

Baby's Development

• Considered full term at 37 weeks

• Continuing to gain weight

• Lungs fully mature

• Ready for birth

Your Signs

• Engagement (baby drops into pelvis)

• Mucus plug may discharge

• Possible water breaking

• Regular contractions signal labor

Final Preparations

• Hospital bag packed

• Birth plan finalized

• Emergency contacts ready

• Install car seat

Common Pregnancy Symptoms by Trimester

First Trimester

• Morning sickness

• Extreme fatigue

• Breast tenderness

• Frequent urination

• Food aversions/cravings

Second Trimester

• Reduced nausea

• Baby movements

• Backache

• Skin changes

• Increased energy

Third Trimester

• Shortness of breath

• Heartburn

• Braxton Hicks contractions

• Swelling

• Difficulty sleeping

Nutrition During Pregnancy

Essential Nutrients

Folic Acid

• 400-800 mcg daily

• Prevents neural tube defects

• Found in leafy greens, fortified cereals

Iron

• 27 mg daily

• Supports increased blood volume

• Found in red meat, beans, fortified foods

Calcium

• 1,000 mg daily

• Baby's bone development

• Found in dairy, leafy greens

Protein

• 71 grams daily

• Essential for growth

• Found in lean meat, eggs, legumes

Foods to Avoid

• Raw or undercooked meat

• Unpasteurized dairy products

• High-mercury fish

• Raw eggs

• Alcohol

• Excessive caffeine

Exercise During Pregnancy

Safe Activities

• Walking

• Swimming

• Prenatal yoga

• Stationary cycling

• Light strength training

Avoid

• Contact sports

• Activities with fall risk

• Hot yoga

• Exercises lying flat on back (after first trimester)

Warning Signs to Watch For

Call Your Doctor Immediately If You Experience:

• Severe abdominal pain

• Heavy vaginal bleeding

• Severe headache

• Vision changes

• Sudden swelling

• Decreased fetal movement

• Fever over 100.4°F

• Painful urination

• Severe vomiting

Emotional Changes

Common Feelings

• Mood swings

• Anxiety about childbirth

• Excitement about baby

• Worries about being a good parent

• Body image concerns

Coping Strategies

• Join support groups

• Talk to your partner

• Practice relaxation techniques

• Stay connected with friends

• Consider prenatal therapy if needed

Preparing for Baby

Third Trimester Checklist

• Complete nursery setup

• Install car seat

• Pack hospital bag

• Stock up on baby essentials

• Prepare freezer meals

• Line up postpartum support

Hospital Bag Essentials

• Comfortable clothing

• Toiletries

• Phone charger

• Birth plan copies

• Baby coming-home outfit

• Car seat

Partner's Role

How Partners Can Help

• Attend prenatal appointments

• Help with household tasks

• Provide emotional support

• Learn about labor and delivery

• Prepare for baby's arrival

• Be patient and understanding

Postpartum Planning

Prepare For

• Physical recovery

• Emotional changes

• Breastfeeding challenges

• Sleep deprivation

• Visitor management

• Pediatrician appointments

Conclusion

Every pregnancy is unique. While this guide provides general timelines, your experience may differ. Regular prenatal care, healthy lifestyle choices, and staying informed are key to a healthy pregnancy.

Remember:

• Trust your instincts

• Ask questions during appointments

• Don't compare your pregnancy to others

• Take care of your mental health

• Enjoy this special journey

Use our Pregnancy Calculator to track your due date, find out how far along you are, and get week-by-week information personalized to your pregnancy timeline.

Disclaimer: This guide is for informational purposes only. Always consult your healthcare provider for personalized medical advice.