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Feb 28, 2022

How does the pregnancy due date calculator work?

When you see the two pink lines on the Prega News pregnancy test kit, you start thinking about the day you will hold your little one in your arms. For every expectant couple, that’s the day they embrace the new role in their lives and embark on the journey of parenthood. Luckily, Prega News offers you a due date calculator that can help you get a better idea of when to expect your newborn’s arrival. After the pregnancy test kit use, you can check on the calculator to get an estimate of your due date - this date is calculated by factoring in various things. And if you are wondering when to take the pregnancy test calculator, you can take it as soon as you find out that you are pregnant! Let's take a deeper dive into it, to understand the pregnancy test date calculator.

 Determining the Date of Conception

 Conception is the day when it is estimated that you become pregnant. However, this is always an estimated date as determining the exact date of conception is not possible as pinpointing the exact ovulation period can be a challenge. So the date of conception is calculated as eleven to twenty one days after the first day of your last period. Some may give an estimate of two weeks after the first day of your last period. This date is the time when your ovulation is likely to occur and when your chances of getting pregnant are at the highest. This is considered to be the most fertile window in a woman’s menstrual cycle, and as such is considered as the date of conception. Another way to determine this is tracking your ovulation symptoms or using ovulation test strips to keep a track of your ovulation period.

 Determining the Estimated Due Date

 As pregnancies last around 40 weeks from the date of start of last periods or 38 weeks from the date of conception, the estimated due date is calculated by adding 280 days to the first day of your last menstrual period. Most doctors and physical practitioners will use this calculation to determine the estimated due date of your baby. However, this is still an estimate or an approximate date and not the exact date of your delivery. Your doctor will also use other methods like ultrasound scans, calculating when the baby's heartbeat is heard for the first time, when movement is felt for the first time and more to give you a better estimate of the due date. As you progress along your pregnancy, your doctor will keep you updated on when to expect the baby’s arrival.

 How does it work?

 The pregnancy test calculator or due date calculator uses the date of your last menstrual cycle and your average cycle length to determine the approximate date of ovulation, and thus the estimated date of conception. To the date of conception, 38 weeks are added or 280 days are added to the first day of your last menstrual cycle to calculate the estimated due date of your baby.

 How accurate is it?

 Any due date calculator is always an estimated due date and not an exact date, as there can be many factors affecting the same. It is based on an estimatationof your ovulation period and thus your date of conception. However, the ovulation period can be amiss by a few days, thus offering an estimated due date. Moreover, as you advance in your pregnancy, many factors like the baby’s growth, your vitals like blood pressure, sugar etc. will help estimate the due date more clearly. Your doctor will also suggest tests and check the baby’s growth to come up with a due date.

 Key takeaway

 While the due date calculator can be used to get an approximate due date, only your doctor will be able to give you the closest possible date. Even with all the tests, ultrasound scans and health check-ups, the practitioners can give an approximate date  for the baby’s arrival. The due date is estimatedto give you an idea of the week or days to watch for symptoms like water breakage, discharge etc., in which case you should immediately contact the doctor. It is also a good idea to keep a hospital bag ready a few days before the due date, so you are always prepared to check-in for the birth of your baby, without any last minute hassles.


 How do you calculate pregnancy weeks from the due date?

You can subtract 38 weeks from your due date to calculate the approximate day you became pregnant

 Why do doctors add 2 weeks to pregnancy?

 As the exact date of ovulation cannot be determined exactly, the two weeks are added to make up for the time between the first day of your last period and the expected date of conception. The expected date of conception is calculated as per the ovulation period which occurs approximately two weeks after the first day of your last period.

Can you find out the exact day you got pregnant?

It is very difficult to determine the exact date when you got pregnant. If you have been using an ovulation tracker or an ovulation test strip, you can get the date which is the most approximate date of you getting pregnant as this is considered to be the most fertile window. However, even with all this information at hand, one can only calculate an approximate date of conception.

How accurate is the due date?

The due date is always an approximate date and your doctor will be able to give you a more accurate one, depending on your tests and ultrasound scans. Moreover, as you advance in your pregnancy, many factors can determine the due date of the baby’s arrival. You can use the due date to be better prepared for your baby’s arrival by having the hospital bag ready, setting up the nursery and shopping for your baby’s essentials well before the D-day.

Can my due date change in third trimester?

Yes, as with all things in nature, your due date too can change at any given point and even in your third trimester. Keep checking-in with your doctor and keep an eye out for any physical changes, pain or urge to pee more frequently, to understand when you should contact your doctor immediately, as these symptoms can tell you that your baby is ready to meet you! 


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