Why is it important to calculate the weeks of pregnancy?
Knowing your current pregnancy week is essential for tracking your baby's development, planning medical checkups, and experiencing every stage of motherhood with peace of mind. Calculating your pregnancy weeks helps you understand the changes in your body, anticipate symptoms, and know when is the right time for ultrasounds, tests, and essential birth-related purchases.
How to calculate pregnancy weeks
Pregnancy is counted in weeks from the first day of the last menstrual period (LMP), not from the day of conception. This is because the precise moment of conception is often difficult to determine. A normal pregnancy lasts an average of 40 weeks, divided into three trimesters.
First day of last menstruation method
Mark the first day of your last period. Add 280 days (about 40 weeks) to get your due date. Each week after that starting date represents your new gestational week.
Ultrasound method
During the first trimester, ultrasound is very accurate in determining your actual pregnancy week. Your doctor will measure the fetal length (CRL – Crown-Rump Length) to accurately determine your pregnancy stage.
Guideline table: weeks and months of pregnancy
- 1–4 weeks: 1st month
- 5–8 weeks: 2nd month
- 9–13 weeks: 3rd month
- 14–17 weeks: 4th month
- 18–22 weeks: 5th month
- 23–27 weeks: 6th month
- 28–31 weeks: 7th month
- 32–35 weeks: 8th month
- 36–40 weeks: 9th month
What to know for each quarter
1st trimester (0–13 weeks)
The body adapts quickly to pregnancy. This is the time of initial tests, the first ultrasound, and often the first symptoms (nausea, fatigue).
2nd trimester (14–27 weeks)
This is generally the most peaceful trimester. The belly grows, symptoms subside, and you begin to feel the baby's first movements.
3rd trimester (28–40 weeks)
The body prepares for childbirth. It's time for final tests, packing the hospital bag, and attending antenatal classes.
Practical advice for expectant mothers
- Use an app or calendar to track each week
- Keep a journal of any symptoms or changes you notice
- Refer to your gynecologist for ultrasound confirmation
- Adapt your lifestyle and diet according to your gestational stage
Conclusion
Tracking your pregnancy weeks helps you live every moment with greater awareness. Whether you're at the beginning or close to giving birth, knowing your current week allows you to make better decisions for yourself and your baby. Time flies: week after week, you're giving birth to a great love.
Frequently Asked Questions (FAQ)
How exactly do you count the weeks of pregnancy?
From the first day of your last menstrual period. Every completed 7 days equals a new gestational week.
Can I calculate pregnancy from the day of conception?
It's not recommended. The standard method starts from the first day of your last period because it's easier to track.
When does pregnancy begin: at conception or fertilization?
Clinically, it is considered to start on the first day of the last menstrual period, not at fertilization.
How can I find out when my due date is?
Add 280 days (40 weeks) to the first day of your last menstrual period to estimate your due date.
