What if I don't know my LMP date?

If you don't remember your last menstrual period date, your healthcare provider can estimate your due date using ultrasound measurements. Early pregnancy ultrasounds (done in the first trimester) are quite accurate for dating pregnancies. You can also use conception date or IVF transfer date if known, though this calculator requires LMP date.

What are the three trimesters?

Pregnancy is divided into three trimesters: First Trimester (weeks 1-12) involves early development and organ formation. Second Trimester (weeks 13-26) is often called the 'golden period' with reduced nausea and increased energy. Third Trimester (weeks 27-40) involves final growth and preparation for birth. Each trimester brings different symptoms, developments, and medical checkups.

Why is pregnancy counted from LMP?

Pregnancy is counted from the first day of your last menstrual period (LMP) rather than conception date because LMP is easier to identify accurately. Conception typically occurs around 2 weeks after LMP (during ovulation), but the exact date is often unknown. This dating method has been the medical standard for decades and is used worldwide.

Can my due date change?

Yes, your due date may be adjusted by your healthcare provider based on ultrasound measurements, particularly early pregnancy scans. First trimester ultrasounds are the most accurate for dating. Your provider may also consider factors like your cycle length if it's significantly different from the standard 28 days. However, due dates are only estimates, and most babies are born within two weeks before or after the predicted date.

Pregnancy Calculator - Due Date & Week Calculator

Calculators / Date Calculators / Pregnancy Calculator

Calculate Your Due Date

Enter the first day of your last menstrual period (LMP) to calculate your estimated due date, current pregnancy week, and trimester information.

Your Pregnancy Information

Additional Details

Pregnancy Timeline

First Trimester (Weeks 1-12)

Early development, morning sickness may begin, first prenatal visits

Second Trimester (Weeks 13-26)

Baby movements felt, anatomy scan, increased energy levels

Third Trimester (Weeks 27-40)

Final growth phase, preparing for birth, regular checkups increase

This calculator provides estimates based on average pregnancy duration. Your healthcare provider may give you a different due date based on ultrasound measurements and other factors. Always consult with your doctor for accurate pregnancy monitoring.

Frequently Asked Questions

The pregnancy calculator provides an estimate based on the standard 280-day (40-week) pregnancy duration from your last menstrual period. However, only about 5% of babies are born exactly on their due date. Your healthcare provider may adjust your due date based on ultrasound measurements, especially early pregnancy scans which can be accurate within a few days.

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