How Can You Calculate Weeks Of Pregnancy
Calculating the exact week of pregnancy is something many women find very tricky. For example, if you are in the middle of week ten of pregnancy, your doctor may say that you are nine weeks pregnant. However, the developmental milestones are matched for week ten of pregnancy. This confusion arises because of the way it is addressed.
Just like the calculation of age, the number of weeks completed is usually considered for indicating the gestational age. The number of weeks you are into pregnancy is different from the number of weeks of pregnancy you have completed. So, while stating the stage of your pregnancy, you can say that you are nine weeks pregnant or in week ten of your pregnancy. Both are correct and accepted ways of quantifying the stage of pregnancy.
What Are The Three Trimesters In Pregnancy
The pregnancy period is divided into three, three-month segments known as trimesters. The division helps understand the changes in the body.
First trimester: It lasts from week one to week 13, when you experience nausea and tiredness.
Second trimester: It lasts from week 14 to week 28. You will feel much better in this period, and your pregnancy bump will be seen. Early pregnancy symptoms such as morning sickness, headache, dizziness, fatigue, etc., slowly disappear.
Third trimester: It lasts from week 29 until you deliver the baby. You will require extra energy to help your baby grow and beat the tiredness .
Why Is It Important To Calculate My Due Date
Its important to know your due date for planning purposes knowing your expected delivery date helps you prepare to welcome your baby. Youll have time to pack for the hospital and get the things you need for the baby, like a car seat. If you have other children, counting down the days until the new baby arrives can help siblings prepare for a new family member.
Knowing when youre due also allows you to get appropriate prenatal care. This includes taking prenatal vitamins and getting prenatal screenings at the right times during your pregnancy. Your provider will also measure your babys size and position throughout your pregnancy to ensure that your baby is growing properly.
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How Do I Calculate My Due Date If I Had Ivf
If you used embryo cryopreservation and in vitro fertilization to get pregnant, you can use your IVF transfer date to calculate your due date. If your provider transferred the embryos five days after they retrieved your eggs, count ahead 261 days from the transfer date.
If your provider transferred the embryos three days after egg retrieval, count ahead 263 days to determine your due date. On your transfer day, your provider will calculate your due date and share this information with you.
Working Out Your Due Date
Once you have confirmed that you are pregnant, you will want to find out when your baby is due to arrive. The average pregnancy is calculated at 282 days from the first day of your last menstrual period.
However babies rarely keep to an exact timetable, so a full-term pregnancy can be anywhere between 37 and 42 weeks. A baby born before 37 weeks is considered to be premature and anything past 42 weeks is considered overdue.
Due dates are usually calculated on your last period instead of the date of conception because of a number of reasons.
- Although the average woman ovulates approximately 2 weeks after her period, the exact time is not always known.
- Once an egg has been released, it can remain fertile for up to 24 hours.
- Sperm can last for up to 5 days after intercourse to fertilise an egg.
If your periods are irregular or you are unsure of the date, an ultrasound will help determine the development of the embryo and your due date. Ultrasound scans can be done at any stage of pregnancy after the first 6 weeks. The best timing for an ultrasound to determine the due date is between 8 weeks and 13 weeks 6 days.
You can use the Pregnancy, Birth and Baby due date calculator to work out when your baby is due.
Some doctors will refer to your due date as ‘expected date of confinement’ or EDC.
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How Can I Calculate How Far Along I Am And My Due Date
If you know the date of the first day of your last menstrual period, or the date of conception, the easiest way to get an estimate of how far along you are is by using the Pampers due date calculator.
Get ready for your baby’s arrival by finding out your estimated due date.
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Do Hcg Levels Change With Twins
If you are carrying twins or multiples, your hCG levels will also increase rapidly during the first few weeks of pregnancy and peak around week 10 just like in a singleton pregnancy. However, there is a chance that your overall hCG levels will be up to 50% higher than what is considered the normal range for a single pregnancy.
Bear in mind though that this is not the case for every pregnancy with twins or multiples. You can still have a successful multiple pregnancy even if your hCG levels measure within the normal range.
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The Weeks Of Pregnancy Method
The second and more official way to calculate your pregnancy is through lunar months or weeks. This is the method that most doctors use and the method by which most experts measure fetal development. How does it work? Each lunar month consists of four weeks, of seven days each. A normal pregnancy will last 280 days from the date of your last menstrual period. And heres the confusing part that means your pregnancy will be 40 weeks or ten months long, measuring in terms of lunar months.
To put this method to work, lets go back to the first example again: Youre pregnant, and the first day of your last menstrual period was January 1. Youll still have an estimated due date of October 8. But at the time of your ovulation, about January 15, you will have been considered two weeks pregnant. By the time you miss your period, you will be considered four weeks pregnant.
Using this scale, your first trimester would be between conception and 13.5 weeks, your second trimester would be from 13.5 to 27 weeks, and your third trimester would be 27 to 40 weeks.
Of course, all of these calculations assume that you have a standard 28-day menstrual cycle. If your cycle is longer or shorter, you will need to adjust your due date calculation. You may also need to make adjustments if youre not sure about the first day of your last menstrual period, especially if you tend to have irregular cycles or spotting.
Why Is Pregnancy Calculated From The Start Of Your Last Period
The ovulation period during which fertilisation happens typically falls two weeks after the menstrual cycle. Many people do not know the exact date of conception but mostly remember the date of their last menstrual period. The time period of forty weeks is added to the LMP to get a tentative due date. During the first two weeks after LMP, you may just be ovulating and getting ready for fertilisation. However, the 40-week time period added to LMP accounts for these non-pregnant time periods. Additionally, this calculation is based on the assumption that your menstrual cycle occurs once every 28 days.
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Does Pregnancy Last For Nine Months
The total time period of pregnancy is considered 40 weeks from LMP. This superficially looks like ten months, assuming each month is made of four weeks. However, in this calculation, it has to be remembered that the actual fertilisation and conception happens two weeks after the last day of the menstrual period. Additionally, some of the months have 31 days and some have 30 days, except February. As an average, every month has 4.4 weeks and not 4 weeks exactly. Based on this, the effective pregnancy period from conception to delivery which is taken as 40 weeks, translates to nine months and one week.
Acog Definition Of Pregnancy
- Early-term: 37 weeks through 38 weeks and six days
- Full-term: 39 weeks through 40 weeks and six days
- Late-term: 41 weeks through 41 weeks and six days
- Post-term: any pregnancy that goes beyond 42 weeks
Sometimes, when talking about twins or triplets, you will hear people say things like, Twins are full-term at 37 weeks. But this isnt truly accurate. All pregnanciesincluding twins, triplets, or morearent truly full-term until they reach 39 weeks.
While you might be at greater risk of earlier labor with twins, that doesn’t affect how the timing of labor would be classified.
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Your Due Date Is Usually Not Your Baby’s Birthday
Every pregnant woman knows that when you are pregnant, the countdown to your due date begins the day of conception. But what is clear is that what you think is your due date may not be your baby’s actual birthday.
There are 266 days from the day of conception to your “due date” or 280 days if you count from the first day of the last period.
The babyMed pregnancy due date calculator gives you a great way to calculate the days up or down.
However, what seems to be a simple question When are you due? is really not that simple. Only 5% of babies are actually born on their due date, and most are born before their due date.
Tips For Moms Partner
Many times the male partner does not feel he has a role in a potential pregnancy at this time. However, his health and lifestyle can also affect your future baby. He may need to evaluate his nutrition, medication intake, as well as habits like smoking, and using drugs or alcohol.
Men can also benefit from taking prenatal vitamins or another type of vitamin supplement, including a proper diet, prior to conception.
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Factors Affecting Due Date
With so much focus and excitement over an assigned day, youd think itd be an accurate numberbut its not always the case. The simple truth is that only 5 out of 100 women will deliver their babies on their actual due date.
Still, determining which week of pregnancy youre in is crucial to receiving good prenatal care and planning for your upcoming life change.
The majority of babies are born over a 35-day span, with birth occurring anywhere from about 37.5 weeks to 42.5 weeks. Due dates also not deadlines. You could have your baby a week later than your due date and still be considered on time.
There are many factors that can influence your due date.
- Each pregnant person has their own predetermined schedule. Many people will tell you that their pregnancies were all about the same length. If you had two kids, each delivered around 41 weeks, your third kid is likely to arrive around 41 weeks.
- People pregnant for the first time tend to go into labor later. Youre more likely to go a few days past your due date with your first baby.
- Some people are at risk of preterm labor. About one in 10 pregnancies end with premature delivery. Maternal risk factors for prematurity babies include having a previous preterm birth, vaginal bleeding during pregnancy, diabetes, high blood pressure, smoking, and even periodontal disease.
Actual Length Of Pregnancy
The actual length of pregnancy varies significantly among women. Just 4% of babies are born on their estimated due date, while 70% are born within ten days. The remaining 30% are born more than ten days before the due date or more than ten days after.
The reference above provides a delivery birth range of 38 weeks and four days to 41 weeks and three days with a probability of 70%.
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Average Length Of Pregnancy
While 40 weeks is the average, its not unusual to deliver your baby earlier or later. In the past, 37 weeks was considered to be a full-term pregnancy. This definition carried implications on as two when it would be safe to induce labor or schedule a cesarean section.
However, we now know that being born at 37 weeks can increase health risks. Its not nearly as risky as being born before 37 weeks, but its not ideal either.
In response, the American College of Obstetricians and Gynecologists has created new definitions to describe the timing of labor:
Drawbacks Of Using Gestational Age
Due date predictions are not always accurate to some degree, theyre an assumption. Some pregnant people even report their health care providers changed their due dates in the third trimester. In most cases, the due date based on a first-trimester ultrasound is considered the most accurate.
If the first ultrasound is performed after 22 weeks of gestation, it wont be quite as accurate in estimating the due date. In this case, the pregnancy will not be considered optimally dated.
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How To Do A Kick Count
There are many different ways to do a kick count. Here is the “count-to-ten” method to do the Kick Count :
- Count fetal movements once a day, preferably at the same time every day and within 1 to 2 hours after a meal. Early evening after dinner is a good time because the fetus is usually more active then.
- Get a sheet of paper and pen to indicate the movements.
- Have a clock or watch nearby to observe the time passed.
- Lie on your side while counting, preferably on your left side.
- Count any movement you feel – a roll, a kick, or a “swish” – except for the smallest flutters.
- Count until you have felt ten fetal movements.
- Ideally, you want to feel at least 10 movements within 2 hours. Most likely you will feel 10 movements in much less time
Talk to your doctor or midwife about what you should do if there’s a problem with your baby’s movements. Many providers ask their patients to contact them or go to the labor and delivery unit if:
- You don’t feel your baby move all day.
- It takes progressively longer from one day to the next to count four movements.
- It takes more than an hour to count four movements.
You might want to start a notebook of your own or use a fetal kick chart to record the time you start, place a checkmark for the time of the 10th movement. This will help you observe patterns and discover how long it normally takes for your baby to move 10 times. Keep in mind that you are looking for significant deviations from the pattern.
How Does The Pregnancy Due Date Calculator Work
- Add 280 days to the first day of your last menstrual period .
- Your menstrual period and ovulation are counted as the first two weeks of pregnancy. This is why a pregnancy ovulation calculator is helpful to pinpoint the exact ovulation cycle.
- If you deliver on your due date, your baby is actually only 38 weeks old, not 40.
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What Is The Best Time And Position To Do The Kick Count
Try to schedule the kick count during your baby’s most active time of day, but also when you will be able to record movements over three or four hours. You will need to record movements starting from about the same time each day.
You may want to have a meal or snack before starting as you probably have noticed, food often makes your baby active. Alternatively, try a few minutes of exercise or take a brisk walk. Some moms prefer sitting with a good backrest with their arms holding their belly. Other moms prefer lying on their left side, which they find most effective for monitoring their baby. Lying on your left side also allows for the best circulation which could lead to a more active baby. Be sure you have a clock in view, and note on the kick count chart what time you start to record movements.
How To Calculate Weeks Of Pregnancy
Pregnancy is calculated based on your last menstrual period. Week one of your pregnancy will start on the first day of your LMP. Likewise, the following weeks are calculated. This may sound weird, but it helps in giving the exact date for timely medical care. Unless you had an assisted conception and knew when the fertilization took place, the LMP method is the only way to know the closest ovulation and conception dates.
The doctors can help you with the exact calculation of weeks and months of pregnancy through other ways.
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How Do You Track Ovulation
A womans monthly cycle is measured from the first day of her menstrual period until the first day of her next period. On average, a womans cycle normally is between 28-32 days. Ovulation is calculated by starting with the first day of the cycle, which is the day the menstrual period begins.
Most women ovulate on any one day between Day 11 Day 21 of their cycle. This is what many refer to as the fertile time or fertility window of a womans cycle because sexual intercourse during this time increases the chance of pregnancy.
For more information on tracking ovulation please see:
If you are taking prescription drugs, check with your health care provider to see if such medication is safe to take during pregnancy. For more information on nutrition during pregnancy, please see our information on pre-conception nutrition.