Pregnancy Week Calculator Last Period

Pregnancy Week Calculation:

\[ Week = \lfloor \frac{\text{Current Date} - \text{LMP}}{7} \rfloor \]

Pregnancy Week:

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What Is Pregnancy Week Calculator Last Period?

The Pregnancy Week Calculator Last Period estimates gestational age based on the first day of your last menstrual period (LMP). This is the standard method used by healthcare providers to track pregnancy progression and estimate due dates.

2. How Does The Calculator Work?

The calculator uses the following formula:

\[ Week = \lfloor \frac{\text{Current Date} - \text{LMP}}{7} \rfloor \]

Where:

\( Week \) — Current pregnancy week
\( Current Date \) — Today's date or selected date
\( LMP \) — First day of last menstrual period
\( \lfloor \rfloor \) — Floor function (rounding down)

Explanation: The calculation counts the number of complete weeks from the first day of your last period to the current date, providing the current gestational week.

3. Importance Of Pregnancy Week Calculation

Details: Accurate pregnancy dating is essential for monitoring fetal development, scheduling prenatal tests, determining due dates, and identifying potential complications. Healthcare providers use this information to ensure proper prenatal care throughout pregnancy.

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 based on these dates. Ensure dates are entered in the correct format (YYYY-MM-DD).

5. Frequently Asked Questions (FAQ)

Q1: Why Use LMP Instead Of Conception Date?
A: LMP is used because it's typically easier to remember and more reliably documented than conception date. Pregnancy dating traditionally starts from LMP, adding approximately two weeks before actual conception occurs.

Q2: How Accurate Is This Calculation?
A: This method provides a good estimate, but ultrasound measurements in early pregnancy (6-13 weeks) are more accurate for dating. The LMP method assumes a regular 28-day cycle with ovulation on day 14.

Q3: What If I Have Irregular Periods?
A: If you have irregular cycles, the LMP method may be less accurate. An early ultrasound provides the most reliable dating in such cases. Consult your healthcare provider for personalized assessment.

Q4: When Should I See A Doctor?
A: Schedule your first prenatal appointment around 8 weeks of pregnancy. Earlier visits may be recommended if you have medical conditions or pregnancy concerns.

Q5: How Is Due Date Calculated?
A: The estimated due date (EDD) is typically calculated as LMP + 280 days (40 weeks). This is known as Naegele's rule: add 1 year, subtract 3 months, and add 7 days to LMP.