How is the pregnancy week calculated?

It is calculated by counting from the first day of the last menstrual period. Every 7 days counts as one week of pregnancy.

Is this a reliable estimate?

Yes, it is the standard method used by gynecologists and obstetricians as an initial reference. It is later adjusted with ultrasounds.

What if I don’t remember the exact date?

You can use the closest estimated date. The tool will provide a general estimation, but it is always recommended to confirm with a specialist.

How to Calculate Your Pregnancy Week

The pregnancy week is calculated from the first day of your last menstrual period—not from the day of conception. This is because many women can’t pinpoint exactly when they ovulated or conceived, but they usually remember the start date of their last period.

This method is used by gynecologists and obstetricians for clinical follow-ups, estimating key dates, and scheduling medical checkups. Every 7 days from that date counts as one week of gestation.

With this tool, you can quickly find out:

Your exact pregnancy week
Your current cycle day
A clear estimate without manual calculations

🛠️ How to Use the Pregnancy Week Calculator

Using the calculator is very easy. You just need to enter the first day of your last period.

The tool does the rest automatically. Based on that date, it:

Calculates the total number of days passed
Divides that number by 7 to determine the pregnancy week
Tells you, for example, that you are in week 13 and 2 days

💡 Tip: If you’re not sure of the exact date, enter the closest one you remember. The tool will give you a general estimate.

📊 Interpreting the Result

The result will show your current pregnancy week and how many days have passed within that week. For example:

“You are in week 15 and 3 days” → means 15 weeks and 3 days have passed since your last period.
“Total pregnancy days: 108 days”

This information is useful for:

Scheduling doctor appointments
Planning prenatal tests
Keeping personal pregnancy records

❓ Frequently Asked Questions About Pregnancy Weeks

Why is it counted from the last period?

Because in most pregnancies, the exact date of conception is unknown. Counting from the period ensures a standard and reliable method.

Can the week change after an ultrasound?

Yes. In some cases, the doctor may adjust the gestational age if there’s a significant difference between fetal size and the estimated date.

How accurate is this calculator?

It’s accurate as a starting point. The final follow-up is defined by clinical and ultrasound confirmation.

Does it count natural days or exact weeks?

It counts natural calendar days, dividing them into blocks of 7 to determine the current week and days within it.

✅ Conclusion and Complementary Tools

Knowing your current pregnancy week helps you make better decisions, prepare for appointments, and track your pregnancy reliably. This tool simplifies the calculation with just one piece of data.

You can also use other helpful tools to support your process: