How Many Weeks Pregnant Am I?

About How Many Weeks Pregnant Am I?

Welcome to our Pregnancy Week Calculator, a comprehensive tool designed to help expecting mothers track their pregnancy journey. Whether you know your due date, last menstrual period (LMP), or conception date, this calculator instantly shows you how many weeks pregnant you are, along with trimester progress, baby size comparisons, and important developmental milestones.

How Pregnancy Weeks Are Calculated

Pregnancy is typically calculated from the first day of your last menstrual period (LMP), not from conception. This is the standard method used by healthcare providers worldwide. A full-term pregnancy is considered 40 weeks (280 days) from the LMP, even though actual conception typically occurs about 2 weeks after the LMP.

Calculation Methods Explained

• From Due Date: If your doctor has given you a due date, we calculate backwards 280 days to determine your LMP, then calculate your current week from there.
• From Last Menstrual Period (LMP): The traditional method - we count the days from the first day of your last period to today and convert to weeks.
• From Conception Date: If you know when conception occurred (such as with IVF), we add 2 weeks to account for the difference between gestational age and fetal age.

Understanding the Three Trimesters

Baby Size Week by Week

One of the most exciting aspects of pregnancy is watching your baby grow! Here are common size comparisons used throughout pregnancy:

Important Pregnancy Milestones

First Trimester Milestones (Weeks 1-12)

• Week 4: Implantation occurs, positive pregnancy test possible
• Week 6: Heartbeat can be detected on ultrasound
• Week 8: All major organs have begun forming
• Week 10: Baby officially called a fetus (no longer embryo)
• Week 12: Risk of miscarriage drops significantly

Second Trimester Milestones (Weeks 13-26)

• Week 16: Baby can hear your voice
• Week 18-20: Anatomy scan ultrasound, gender can be determined
• Week 20: Halfway point! You may feel first movements (quickening)
• Week 24: Viability milestone - baby has a chance of survival if born early

Third Trimester Milestones (Weeks 27-40)

• Week 28: Eyes can open and close
• Week 32: Baby practices breathing movements
• Week 36: Baby is considered "early term"
• Week 37: Baby is considered "full term"
• Week 39-40: Optimal time for delivery

Frequently Asked Questions

Tips for a Healthy Pregnancy

• Prenatal vitamins: Start taking folic acid before conception and throughout pregnancy
• Regular checkups: Attend all prenatal appointments as scheduled
• Balanced diet: Eat plenty of fruits, vegetables, lean proteins, and whole grains
• Stay hydrated: Drink at least 8-10 glasses of water daily
• Exercise: Maintain moderate physical activity (consult your doctor first)
• Rest: Get adequate sleep, especially during the first and third trimesters
• Avoid harmful substances: No alcohol, tobacco, or recreational drugs

When to Contact Your Healthcare Provider

While this calculator helps track your pregnancy, always consult your healthcare provider for medical advice. Contact them immediately if you experience:

• Vaginal bleeding or fluid leakage
• Severe abdominal pain or cramping
• Sudden swelling of face, hands, or feet
• Severe headaches or vision changes
• Decreased fetal movement (after 28 weeks)
• Signs of preterm labor before 37 weeks

Additional Resources

• ACOG - How Your Fetus Grows During Pregnancy
• Mayo Clinic - Pregnancy Week by Week

Related MiniWebtools:

Pregnancy Calculators:

• Due Date Calculator
• How Many Weeks Pregnant Am I?
• Pregnancy Calendar