1. What is the Pregnancy Birthday Calculator?

The Pregnancy Birthday Calculator estimates a baby's due date based on the last menstrual period (LMP) date, adding 280 days (40 weeks) to determine the expected delivery date.

2. How Does the Calculator Work?

The calculator uses the standard pregnancy calculation:

Where:

• LMP Date — First day of last menstrual period
• 280 days — Standard length of human pregnancy (40 weeks)

Explanation: This calculation is based on Naegele's rule, which assumes a 28-day menstrual cycle with ovulation on day 14.

3. Importance of Due Date Calculation

Details: Knowing the estimated due date helps monitor pregnancy progress, schedule prenatal care, and identify potential preterm or post-term pregnancies.

4. Using the Calculator

Tips: Enter the first day of your last menstrual period. For best accuracy, you should know your typical cycle length and ovulation date.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this calculation?
A: About 4% of women deliver on their due date. Most deliver within 2 weeks before or after.

Q2: What if my cycle isn't 28 days?
A: For irregular cycles, ultrasound dating in early pregnancy is more accurate.

Q3: Why 280 days if pregnancy is 9 months?
A: Pregnancy is actually about 9.5 lunar months (4 weeks each). Calendar months vary in length.

Q4: When should I see a doctor?
A: Schedule prenatal care as soon as you suspect pregnancy, typically around 8 weeks from LMP.

Q5: Can the due date change?
A: Yes, early ultrasound may adjust the due date based on fetal measurements.