1. What is Pregnancy Week Calculator?

The Pregnancy Week Calculator determines how far along you are in your pregnancy by calculating the time elapsed since your last menstrual period (LMP). Pregnancy is typically measured in weeks, with a full-term pregnancy lasting about 40 weeks.

2. How Does the Calculator Work?

The calculator uses the following calculation:

Where:

• \( LMP \) — First day of your last menstrual period
• \( Current\ Date \) — Today's date or any date you want to check

Explanation: The calculation counts the number of days between the two dates and converts them to weeks by dividing by 7.

3. Importance of Pregnancy Dating

Details: Accurate pregnancy dating is crucial for proper prenatal care, scheduling tests at the right times, and determining if the baby is growing appropriately. It also helps predict the estimated due date.

4. Using the Calculator

Tips: Enter the first day of your last menstrual period and the current date (defaults to today). The calculator will show how many weeks and days pregnant you are, plus your estimated due date (40 weeks from LMP).

5. Frequently Asked Questions (FAQ)

Q1: Why is pregnancy calculated from LMP and not conception?
A: LMP is used because most women can recall this date, while conception date is often unknown. Pregnancy is traditionally calculated as 40 weeks from LMP (about 38 weeks from conception).

Q2: What if I don't know my LMP?
A: An early ultrasound can estimate gestational age. Without LMP or ultrasound, providers may use fundal height measurements.

Q3: Are all pregnancies exactly 40 weeks?
A: No, 40 weeks is an average. Full-term is 37-42 weeks. Only about 5% of women deliver on their exact due date.

Q4: What if my cycle isn't 28 days?
A: The calculator assumes a standard 28-day cycle. If your cycles are significantly longer/shorter, consult your provider for adjustments.

Q5: When should I see a doctor?
A: Schedule your first prenatal visit as soon as you get a positive pregnancy test, typically around 8 weeks gestation.