1. What Is Pregnancy Week Calculator?

The Pregnancy Week Calculator estimates the current gestational age in weeks based on the last menstrual period (LMP) and current date. This calculation follows standard obstetric dating methods used in New Zealand healthcare.

2. How Does The Calculator Work?

The calculator uses the standard pregnancy dating formula:

Where:

• \( \text{LMP} \) — First day of last menstrual period
• \( \text{Current Date} \) — Today's date or any specified date
• \( \lfloor \rfloor \) — Floor function (rounding down to nearest integer)

Explanation: Pregnancy is calculated from the first day of your last menstrual period, not from conception. This method provides the gestational age used by healthcare providers.

3. Importance Of Pregnancy Week Tracking

Details: Accurate pregnancy dating is essential for monitoring fetal development, scheduling prenatal tests, determining due date, and identifying potential complications. It helps healthcare providers track appropriate growth milestones.

4. Using The Calculator

Tips: Enter the first day of your last menstrual period and the current date (or any date you want to check). The calculator will determine how many weeks pregnant you are at that specific date.

5. Frequently Asked Questions (FAQ)

Q1: Why is pregnancy calculated from LMP instead of conception?
A: LMP provides a consistent starting point that's easier to identify than conception date. This standard method is used worldwide by healthcare professionals.

Q2: How accurate is this calculation?
A: Very accurate for women with regular 28-day cycles. For irregular cycles, ultrasound dating in early pregnancy may provide more precise gestational age.

Q3: What if I don't know my exact LMP?
A: Use your best estimate. Early pregnancy ultrasound (before 14 weeks) can provide accurate dating if LMP is uncertain.

Q4: Does this calculator account for leap years?
A: Yes, the calculation automatically accounts for leap years and varying month lengths when calculating the date difference.

Q5: When should I see a healthcare provider?
A: Contact your healthcare provider as soon as you suspect pregnancy for confirmation and to begin prenatal care, typically around 8-10 weeks gestation.