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Pregnancy Weeks Calculation:
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Pregnancy weeks calculation determines how many weeks pregnant you are based on the first day of your last menstrual period (LMP). This is the standard method used by healthcare providers to date pregnancies and estimate due dates.
The calculator uses the following formula:
Where:
Explanation: The calculation counts the number of complete weeks that have passed since the first day of your last menstrual period.
Details: Accurate pregnancy dating is essential for monitoring fetal development, scheduling prenatal tests at appropriate times, determining gestational age, and estimating the due date for delivery planning.
Tips: Enter the current date (or any date you want to check) and the first day of your last menstrual period. The calculator will determine how many complete weeks pregnant you are on that specific date.
Q1: Why use LMP instead of conception date?
A: LMP is used because it's easier to recall and provides a standardized method for healthcare providers. Pregnancy is calculated from the first day of your last period, not from conception.
Q2: What if I don't know my exact LMP?
A: If you're unsure, use your best estimate. An ultrasound in early pregnancy can provide more accurate dating if LMP is uncertain.
Q3: How accurate is this calculation?
A: This calculation provides a good estimate for women with regular 28-day cycles. For irregular cycles, ultrasound dating may be more accurate.
Q4: When should I see a healthcare provider?
A: Schedule your first prenatal appointment when you get a positive pregnancy test, typically around 8 weeks gestation.
Q5: What's considered full-term pregnancy?
A: Full-term pregnancy is 39-40 weeks. Babies born between 37-38 weeks are early term, and 41+ weeks are post-term.