Pregnancy Guide & Tools

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Content reviewed against published ACOG, AAP, CDC guidelines

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Evidence-based pregnancy resources to help you track your pregnancy, prepare for delivery, and understand what to expect at each stage.

Key takeaways

  • A full-term pregnancy is 39-40 weeks, divided into three trimesters
  • Morning sickness typically peaks at weeks 8-10 and improves in the second trimester
  • The anatomy scan happens at weeks 18-22
  • Call your provider immediately for vaginal bleeding, severe headache, or decreased fetal movement
  • Pack your hospital bag by week 36

Pregnancy tools & calculators

Pregnancy guides

What happens in the first trimester?

Weeks 1-12

  • All major organs begin to form
  • Heart starts beating around week 6
  • Morning sickness peaks around weeks 8-10
  • First prenatal visit typically between weeks 8-12
  • Nuchal translucency screening at weeks 11-13
  • Risk of miscarriage decreases significantly after week 12

What happens in the second trimester?

Weeks 13-26

  • Morning sickness typically improves
  • Anatomy scan (detailed ultrasound) at weeks 18-22
  • You may begin to feel baby move (quickening) around weeks 16-22
  • Glucose screening test at weeks 24-28
  • Baby can hear sounds from outside the womb
  • Viability milestone around 24 weeks

What happens in the third trimester?

Weeks 27-40

  • Baby gains weight rapidly, building fat stores
  • Braxton Hicks contractions may begin
  • Group B strep test at weeks 36-37
  • Baby moves into head-down position (usually by week 36)
  • Full term is considered 39-40 weeks
  • Pack your hospital bag by week 36

When should I call my doctor during pregnancy?

Contact your healthcare provider immediately if you experience:

  • Vaginal bleeding
  • Severe abdominal pain or cramping
  • Persistent severe headache with vision changes
  • Sudden swelling of face, hands, or feet
  • Fever above 100.4°F (38°C)
  • Decreased fetal movement after 28 weeks
  • Leaking fluid from the vagina
  • Regular contractions before 37 weeks

Preparing for baby

Frequently asked questions

When is the first prenatal visit?
The first prenatal visit is typically between weeks 8-12 of pregnancy.
When can I find out the sex of my baby?
The anatomy scan at weeks 18-22 can determine sex. NIPT blood testing can reveal sex as early as 10 weeks.
When should I pack my hospital bag?
By week 36. This gives you time before full term (39 weeks) in case baby arrives early.
What is the difference between Braxton Hicks and real contractions?
Braxton Hicks contractions are irregular, usually painless, and stop with rest or position changes. Real contractions are regular, get progressively stronger and closer together, and do not stop with rest.

Bottom line

Pregnancy is a journey with many normal variations. Every trimester brings new changes and new questions. Your OB-GYN or midwife is your best resource for personalized guidance throughout your pregnancy.

Trust your instincts. If something feels wrong, reach out to your pediatrician. Worrying about your baby means you care — that is a good thing.

All content follows our editorial policy and is reviewed against published clinical guidelines.

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