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How to Count Pregnancy Weeks?

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How to count your pregnancy weeks

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Your hormones are exploding, your tummy is growing, and your brain has determined that this is the ideal time to flee the scene. And despite it all, you’re expected to be counting pregnancy weeks? Really, it’s all a bit much.

You are aware that this pregnancy should last about nine months. But how many weeks is that? And when exactly do you begin counting?

While your healthcare practitioner will assist you in staying on schedule, it’s always a good idea to be in control of your own affairs. Making everything about the journey more comfortable may be accomplished by being aware of what to anticipate at each stop. Additionally, creating a mommy community is a good idea. Nothing compares to experiencing everything together.

So, let’s get to it. We’re going to make it easier for you on ‘how to count pregnancy weeks’ so you can cross that task off your list.

How to count pregnancy weeks?

What should you know first?

The typical pregnancy lasts between 38 and 42 weeks.

Despite this, there are outliers on both ends of the spectrum. If your pregnancy lasts longer or shorter than usual, you can still have a perfectly healthy baby and a perfectly healthy mother. Each pregnant woman’s narrative (and timetable) is different. 

When do you actually begin counting pregnancy weeks, then? Attention: the solution might not be as obvious as you believe.

Why does pregnancy start counting with the final period?

Are you ready for something bizarre? You could already be four weeks pregnant when you start counting!

This is due to the fact that Day 1 of pregnancy is determined based on the first day of your most recent menstrual cycle rather than the date of conception.

Why are there 4 weeks in pregnancy at 2 weeks?

Since it’s difficult to determine with certainty when conception occurred, we cannot start our counting from that day. Ovulation is often thought to occur 14 days following the beginning day of your menstrual cycle, although this is not an exact science.

Therefore, the medical community concluded that it would be preferable to begin counting from your LMP’s first day in order to make things simpler.

This implies that even while conception may be just 2 weeks away, the first day of your LMP maybe 4 weeks away, making you appear to be “4 weeks pregnant.”

Pregnancy week counting begins on the first day of your last period and continues up to Week 40 (due date) and is as high as Week 42. 

The fundamental formula is LMP + 280 days = EDD (estimated due date). Another way to look at it is that your doctor will consider you to be one week pregnant on the first day of your most recent menstruation.

Nevertheless, have in mind that this calculation is based on a 28-day menstrual cycle, which is only the typical cycle length. Your due date may change if you have a shorter or longer menstrual cycle than others.

What happens if you can't recall precisely when your most recent period started?

If you’re not used to tracking your cycle with apps or calendars, don’t worry. Some medical professionals will perform an ultrasound to measure your baby’s size early in pregnancy, around seven to eight weeks. 

This ultrasound is called a dating or viability ultrasound; you can request one if your provider doesn’t do it automatically. The embryo’s size aids in reducing the embryo’s development time. You shouldn’t be astonished if your doctor orders you to advance or retreat a week based on the size of your baby since this scan is frequently used as the most reliable indicator of your pregnancy weeks.

How to count pregnancy weeks in the case of IVF?

Your pregnancy week computation will appear slightly different if you become pregnant through in vitro fertilization.

Utilizing recently obtained eggs: Week 2 is counted from the day your eggs were recovered.

When using frozen embryos, week 2 starts on the day of the embryo transfer less the number of days after that. For instance, if a 3-day-old embryo is transferred or implanted on January 12, you’ll be two weeks along by January 9 and can keep adding weeks from that point on. Week 2 of your pregnancy would have begun on June 15 if a 5-day-old embryo were to be implanted on June 20.

Conclusion; getting a date with more accuracy

It is easy to determine how far along you are in your pregnancy by counting back from your last period, however, it isn’t always precise for the following reasons:

  • You might not be completely sure of when your last period began.
  • The interval between your menstruation and ovulation might vary since women’s cycles can have varied lengths.
  • You could be dating your pregnancy from the wrong moment since some women have spotting or bleeding in the early stages of pregnancy, which can occasionally be confused with a period.

It is still possible to determine your precise pregnancy status, despite this. When you get your first ultrasound scan, you’ll learn your due date with the greatest degree of certainty. 

FAQs: How to Count Your Pregnancy Weeks

1. How to determine the weeks and months of your pregnancy?

Pregnancy lasts around 40 weeks, counting from the first day of the prospective mother's last menstrual cycle. Typically, the last menstrual period (LMP) date is used to determine when a woman is pregnant.

2. What does a due date mean?

Human newborns complete their in-utero development in roughly 38 weeks (266 days). Your due date is the day that, depending on this 38-week gestation, you should give birth.




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