Pregnancies are filled with a lot of excitement and anticipation. But one thing that many expectant moms want to know is the due date of their baby.
One of the easiest ways to determine your pregnancy due date is by using an online pregnancy due date calculator. So stick around if you don’t know anything about pregnancy dating. By the end of this article, you should be comfortable using a due date calculator and even be able to calculate your own due date.
How Do You Determine Your Due Date Using a Pregnancy Due Date Calculator?
With advancements in technology, it has become relatively easy for expectant mothers to find out their estimated due date even before they visit their doctor. There are many reliable pregnancy calculators online, and the best part is that most of them are free to use.
Once you have access to an online due date calculator, you can use various methods to estimate your pregnancy due date. We’ve discussed each of these methods below.
How to Determine Your Pregnancy Due Date Based on Last Period
Enter the date of the first day of your last menstrual period:
Your due date is:
Calculating your pregnancy due date based on your last menstrual period is fairly simple. All you have to do is find a reputable online pregnancy due date calculator and fill in the first day of your last menstrual period. You’ll also be asked to fill in your cycle length.
This number is usually 28 days for most women, but some women have longer or shorter menstrual cycles. However, the typical range is between 22 and 42 days. If your menstrual cycle length is longer than the regular 28 days, your estimated due date will be a bit later, and if the cycle length is shorter than 28 days, your estimated due date might come earlier.
Once you have filled in this information, the online calculator should give you an estimated due date. Most calculators and health providers use a method known as Naegele’s Rule to estimate your due date. Since the human gestational age is around 280 days, about 40 weeks, Naegele’s Rule involves adding 40 weeks to the first day of your last menstrual period.
But why the first day of your period? Well, this first day of your menstrual cycle is also considered the first day of your pregnancy, and that’s why it is used to estimate your due date.
How to Determine Your Pregnancy Due Date Based on Conception Date
If you can’t remember the first day of your last menstrual period, you can calculate your due date by filling in the date of conception. This date can be difficult for most women to pinpoint for various reasons. The conception date is the day the sperm and the ovum meet. Contrary to popular belief, it is not the same as the day that a woman had sexual intercourse (even if it was just once during their ovulation period).
Sperm can live in a woman’s body for up to five days. On the other hand, an egg can live for up to 24 hours from when it is released. That means conception can happen anywhere within this 6-day window, making it very hard to predict when conception occurred.
How to Calculate Due Date Using a Pregnancy Wheel
Using a pregnancy wheel is another suitable method to estimate a due date. In fact, many doctors use this tool to evaluate the due date for most pregnancies. If you have access to this pregnancy tool, all you have to do is line up the arrow on the first day of your last menstrual period. Once the arrow is lined up, look at the other indicator at the end of the wheel for your due date.
Like all the other methods mentioned above, this date is just an estimate. So, expect your child’s birth to be two weeks before or after the given date.
How Do I Determine How Many Weeks Pregnant I Am?
To determine how many weeks you’re pregnant, count the weeks since the first day of your last menstrual period.
What if You Don’t Know the Date of Conception or the First Day of Your Last Period?
If you want to know your estimated due date but don’t know the first day of your last menstrual period or the conception date, you’re not alone. If you don’t remember these details, the first step is to visit your doctor for a physical exam. The doctor might ask if you remember the week you had your last period and try to estimate your due date from that information.
If you can’t remember the week you got your last period, the doctor might recommend getting an ultrasound scan. This ultrasound accurately determines a woman’s due date, especially if it’s done between eight and 16 weeks of the pregnancy. Many doctors use the first ultrasound exam at around 12 weeks to give expectant moms an accurate due date. A third-trimester ultrasound is less likely to provide a precise result because babies grow at different rates at this age.
How to Calculate Due Date if You’ve Had IVF
In vitro fertilization or IVF pregnancies are the only cases where the doctor knows the conception date. So, ask the doctor to give you this date. Once you have the egg retrieval date, add 266 days to get your due date.
If you had a three-day frozen embryo transfer (FET), add 266 days and subtract three days. Alternatively, you can use an IVF due date calculator for the baby’s due date. Find a reputable IVF calculator, fill in your IVF transfer date and the type of IVF you had, and the due date calculator will provide you with a due date.
Remember that the dates provided for IVF pregnancies are also estimates. They don’t guarantee that a woman will go into labor that day.
Can My Due Date Change?
Yes, your due date can change based on the calculation method that your doctor uses. For example, there is a high chance that the due date you get from your first-trimester ultrasound scan might not be the same as the one you got on a pregnancy calculator based on your last period, conception date, or even the IVF transfer date. An ultrasound scan is more accurate than the date calculated by a pregnancy calculator.
How Do I Calculate the Day I Got Pregnant?
Pinpointing an exact conception date can be a bit challenging. However, if you know the first day of your last menstrual period, estimating your conception date is pretty simple. Take any number between 11 and 21 and add it to the day of your last menstrual period to get an estimate of the day you got pregnant.
How Soon Can I Take a Pregnancy Test?
You can take a pregnancy test a day after your missed period. However, a few sensitive pregnancy test kits can detect a pregnancy even before a woman misses her period.
Estimating Your Bundle of Joy’s Arrival
While a pregnancy due date calculator is a great way to get your estimated due date, it is not by any means accurate. Only 4% of the babies are born on the date provided on a pregnancy due date calculator. Eighty percent of the babies are born up to two weeks before or after the estimated due date. So don’t be too fixated on the provided delivery date because it is simply an estimate.