Pregnancy Calculator – Track Your Journey
Follow every step of your 40-week adventure. From the first positive test to the final hospital bag packing list, we calculate your key medical and personal milestones.
Last Period Details
Estimated Due Date
Key Dates
Pregnancy is often measured in months by friends, but in Weeks by medical professionals. This calculator bridges that gap, giving you the precise "Week + Day" count that your doctor will ask for at every visit.
Beyond just a due date, this tool outlines the "Critical Periods" of development—when the heart starts beating, when you can find out the gender, and when the baby is considered viable.
Medical Checkpoints
Never miss a test. We calculate the optimal window for your Nuchal Translucency scan (11-13 weeks), Anatomy Scan (18-22 weeks), and Glucose Challenge test (24-28 weeks).
Trimester Breakdown
Each trimester brings unique symptoms and joys. We break down your 9 months into three distinct phases, helping you prepare mentally and physically for the changes ahead.
Fetal Development Timeline
The growth from a single cell to a 7lb baby is miraculous. Here is the high-level roadmap of what is happening inside.
The "4th Trimester"
Don't stop planning at Week 40. The first 12 weeks after birth are often called the Fourth Trimester.
This is a period of immense adjustment for both mom (healing, lactation) and baby (adjusting to light and noise). Preparing for postpartum support is just as important as preparing for the birth itself.
Strategy: The "Safe Pregnancy" Checklist
Optimizing Outcomes
- Weeks 0-12:Folic Acid. Taking 400mcg daily prevents neural tube defects. If trying to conceive, start before you get pregnant.
- Weeks 13-28:Iron & Calcium. Your blood volume increases by 50%. You need extra iron to prevent anemia.
- Weeks 29-40:Kick Counts. Monitoring baby's movement daily helps detect distress early.
The 40-Week Math
Medical professionals calculate pregnancy duration as 280 days (40 weeks) from the first day of the Last Menstrual Period (LMP).
This assumes a 28-day cycle with ovulation on Day 14. If your cycle is longer or shorter, we adjust the "40 weeks" accordingly. This is why "Conception Date" is often 2 weeks after the pregnancy start date.
Your Body: What to Expect
The "Silent" Phase
Baby: Developing nervous system.
Mom: Nausea, fatigue, breast tenderness.
To-Do: NIPT Screening (Week 10).
You may lose weight due to nausea. This is normal.
The Golden Era
Baby: Hearing develops (Week 18).
Mom: "The Glow", energy returns, bump shows.
To-Do: Gender Scan (Week 20).
Best time for a "Babymoon" vacation.
The Final Stretch
Baby: Lungs mature, putting on fat.
Mom: Swelling, sleeplessness, nesting instinct.
To-Do: Car seat install (Week 36).
Rest as much as possible. Sleep while you can!
Related Tools
Can I fly while pregnant?
Generally, yes, up until 36 weeks (domestic) or 28-35 weeks (international). However, you should always walk every hour to prevent blood clots (DVT), as pregnancy increases clotting risk.
Is 'Brain Fog' real?
Yes. 'Pregnancy Brain' is a documented phenomenon caused by hormonal surges (progesterone) and sleep deprivation. It is temporary!
Why is the first ultrasound date different from my LMP date?
Ovulation timing varies. An ultrasound measures the physical size of the embryo (CRL), which is the most accurate way to date a pregnancy. If the difference is >7 days, doctors defer to the ultrasound date.
What foods should I absolutely avoid?
High-mercury fish (shark, swordfish), unpasteurized cheese (listeria risk), and raw meat/sushi are the big ones. Deli meats should be heated until steaming.
When will I feel the baby move?
First-time moms typically feel 'flutters' around weeks 18-22. Moms with subsequent pregnancies might feel it as early as week 16.
Obstetrics Dictionary
Trimester
A three-month period. Pregnancy has three trimesters (1st: 1-13 weeks, 2nd: 14-27 weeks, 3rd: 28-40 weeks).
Braxton Hicks
"Practice contractions." Painless tightening of the uterus that prepares the body for labor. They do not dilate the cervix.
Fundal Height
The distance from the pubic bone to the top of the uterus (fundus). After week 20, it typically matches the number of weeks pregnant in centimeters.
Lanugo
Fine, soft hair that covers the fetus to keep them warm. It usually sheds before birth.
About This Calculator
We define pregnancy milestones based on the clinical guidelines set by ACOG (American College of Obstetricians and Gynecologists). This tool is regularly updated to reflect the latest recommendations for prenatal screening windows (like the NIPT and Glucose Tolerance Test).