What If Your Lmp Is Not Known Or Periods Are Irregular
The due date calculation works ideally if your periods are regular, i.e., if they follow a 28-day cycle.
If your periods are irregular or you do not remember your last period, you should wait for your first ultrasound pregnancy scan. Also known as a dating scan, it will provide the number of weeks remaining for your due date .
If the scan does not give the correct results, your doctor may ask you to wait for some more time. Ideally, the dating scan will be done between six and 13 weeks plus six days .
I Had Sex Two Weeks Ago But My Doctor Says That Im Four Weeks Pregnant How
88 things nobody tells you about being pregnantIf you have a standard 28-day period, you will likely ovulate around day 14 and are most fertile around days 12, 13 and 14when you had sex to conceive. It takes about nine days after ovulation for implantation to occur, which brings you to around day 23. It takes a few days for your pregnancy hormone levels to be detectable by a pregnancy test, bringing you to around day 28. How far along you are in your pregnancy isnt calculated from conception or implantation but from the first day of your last normal period. If you had your period four weeks ago, then ovulated and had sex two weeks ago to become pregnant, youre currently four weeks pregnant.
What If I Dont Know The Date Of My Last Menstrual Period
This is more common than youd think. Luckily, there are ways to figure out your due date when you cant remember the first day of your LMP:
- If you know you had your LMP during a particular week, your doctor can estimate your due date accordingly.
- If you have no idea when your last period was, your doctor may order an ultrasound to determine your due date.
Read Also: Can You Donate Plasma If Your Pregnant
Can The Pregnancy Conception Calculator Be Wrong
Yes, of course. So, when does conception happen? There is no possibility being 100 % sure about it. You may be a little bit more certain if you track your cycle and have it perfectly regular. But even ultrasounds and blood tests aren’t faultless. Remember, that your fertile window begins up to 5 days before ovulation and ends one day after it. So, although your conception date is, e.g., 11 July 2019, the intercourse that caused the pregnancy may have occurred as early as 6 July. However, with our conception calendar calculator, you can make an estimated guess!
Disclaimer About The Calculator
Our calculator strives for the highest accuracy, but your pregnancy progress may differ from the calculator’s results for several reasons including possible miscalculation errors in input data individual variations in the timing of ovulation, and/or conception.
The information provided regarding pregnancy progress and fetal development is a guide through the weeks. It is not specific information for a specific individual but serves as a general guide only. As each pregnancy differs, any dates, weights, and lengths should be considered general information for interest only.
Our week-by-week guides use both standard and metric units of measure including pounds and kilograms.
You May Like: Can You Donate Plasma When Pregnant
How Accurate Is Pregnancy Due Date Calculation
Pregnancy due date calculation is a rough estimate of the likely date at which the baby can be born. Only 5% of babies are born exactly on the due date, while all others are born a few days before or after it. The inaccuracy of LMP date and the variation in the exact date of fertilisation are factors influencing the difference in the actual delivery date and the expected due date.
The anxiety around the due date is a very normal feeling among pregnant women. The due date that the doctor provides usually gives an approximate time frame for all the preparations towards delivering the baby. Weeks, months or trimesters are often used to quantify the stage of pregnancy and you can choose any method that you find convenient.
Can I Plan My Due Date
Whether you’re trying to avoid being very pregnant in the middle of summer or are a teacher who wants to maximize time off with your little one, you can try to time when you conceive in order to “plan” your due date. But even if you’re one of the lucky ones who’s able to get pregnant when she really wants to, just remember that you probably won’t be able to map out exactly when you’ll give birth to the day .
Still, you can try our Ovulation Calculator, which uses the date of your last menstrual period and your typical cycle length to discover the days you’re most likely to be fertile and increase your chances of conceiving.
Also Check: Vagisil When Pregnant
What If You Dont Know Your Lmp Or Your Periods Are Irregular
In the case where you do not know the exact date of your last menstrual period or if you have not had a regular menstrual cycle, the doctor estimates the foetal age through ultrasound imaging. Parameters like the crown-rump length and the foetal sac measurements give an idea about the rough age of the foetus. Based on the foetal age, the expected delivery date is given by the doctor.
How To Calculate How Many Weeks You Are
Example:count one week to the nextuntil you reach the present date.
LMP = December 2, 2021
1st Wed = December 9, 2021 = 1 Week2nd Wed = December 16, 2021 = 2 Weeks9th Wed = February 3, 2022 = 9 WeeksYou are 9 Weeks and 1 Day pregnant
Another method to calculate how many weeks pregnant you are is to:
How Many Weeks Am I Formula:LMP = Last Menstrual PeriodHow Far Along Am I Formula:LMP = Last Menstrual Period*LMP date may be adjusted if unknown or following ultrasound.
Each of these methods will give you the gestational age of your pregnancy.
Don’t Miss: Can I Use Vagisil Wipes While Pregnant
Conception Calculator Based On Lmp
The other method of using the pregnancy conception calculator is to provide the first day of your last menstruation and the average length of your menstrual cycle. The majority of cycles last around 28 days. However, typical values range between 21 and 35 days.
In cycles of 28 days, ovulation happens around 14 days before the beginning of the next cycle. So, if a cycle lasts 28 days, ovulation occurs the 14th day after the first day of the cycle . If it’s shorter, you subtract the corresponding number, e.g., for a 22 days cycle – ovulation occurs on the 8th day. If it’s longer, you add some days, e.g., for a 34 day cycle – ovulation is on the 20th day. For cycles longer than 35 days or shorter than 21 days, these calculations are not applicable and you should consult by a doctor. If you’re not sure how long your cycles are, leave the default number of 28 days.
When does conception happen? How long does conception take? The fertile window begins 3-5 days before the ovulation date, and ends one day after it. It means, to get pregnant, you should have intercourse within this time. Although sperm can survive up to 7 days inside a woman’s body, conception does not happen until ovulation. Therefore, conception day is the day of ovulation and might last for 24 hours after the egg is release. Therefore, the formula to estimate the conception date based on the LMP:
LMP + cycle length – 14 = conception date
How Does The Ivf Pregnancy Week Calculator Work
It is simple to use. To calculate which week of your pregnancy you are in you need to select the date according to:
- Exact day of the egg extraction for them to be inseminated.
- Exact date in which the embryo transfer took place
Once these boxes have been filled in, click the calculate button.
Immediately after receiving your results, you will not only know the week of pregnancy you are in but an approximate delivery date .
Also, knowing what week you are in, you can discover a wide range of information about your future baby, for example its size and weight thanks to the fetal growth calculator, or you can start thinking about what you will call your future baby with our baby name selector tool.
Also Check: Can I Use Vagisil Wash While Pregnant
What Is Naegele’s Rule
For example, if the first day of your last period was August 11, 2019, you would:
- Add 1 year
- Add 7 days
- Move the date back 3 months
- Your due date would be May 18, 2020.
If your fertility app gives you a different date than the one calculated by your doctor, it most likely because it was based on the ovulation date and not the date of your last period. If you ovulated earlier or later than day 14 of your cycle, this would shift your due date accordingly.
Conception Calculator Based On Due Date
So, what day did I conceive? There are two ways to use our conception calendar calculator.
The first way is to provide the birth due date. When you visit the doctor they will most likely perform an ultrasound. Although the doctor can see the baby from the 5-6th week of pregnancy, the best time to go for the first sonography is between week 8 and 12.
Based on the characteristics of the image and the results of your blood test, the due date and week of pregnancy can be determined. Remember that those dates, as well as conception calendar, are only an estimation and may change during the next visit.
Pregnancy typically lasts around 40 weeks . That is 266 days from the conception date. If a baby is born before week 37, it’s called a premature birth. But don’t worry if the due date changes or you go in labor on a different date – only 4% of babies are born on their due date and 80% are born either two weeks before and after the date.
Let’s go back to the question: what day did I conceive? In our conception calculator, we subtract 266 days from the estimated due date and get the most probable day of conception:
due date – 266 = conception date
Recommended Reading: Lasik Eye Surgery And Pregnancy
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.
Using An Online Calculator
Don’t Miss: Can You Donate Plasma When Pregnant
How Many Weeks Months And Trimesters In A Pregnancy
Pregnancy math can get confusing pretty quickly. Are you in week 12 or 13? Your first trimester or your second? Three months pregnant or four?
Fortunately, the answers are simple once you know what to count. Heres what you need to know about how many weeks, months and trimesters there are in a pregnancy and where you fit in.
Calculate Using A Dating Ultrasound
A dating ultrasound, which measures the length of the fetus from crown to rump, is an accurate way to estimate your due date or how far along you are if completed within the first trimester . Most women have a pretty good idea of when their last period was, within a day or two, says Scurfield. If a woman has no idea, youll want to try to get her as early as you can. Once you get past 13 weeks, the variability of the growth is such that an ultrasound can be off by a week or so.
You May Like: How To Calculate Safe Days To Avoid Pregnancy
First Day Of Last Period
Most pregnancies last around 40 weeks , so typically the best way to estimate your due date is to count 40 weeks, or 280 days, from the first day of your last menstrual period .
Another way to do it is to subtract three months from the first day of your last period and add seven days. So if your last period started on April 11, you’d count back three months to January 11 and then add seven days, which means your due date would be January 18.
This is how your doctor will estimate your due date and its a pretty solid target. But remember: Its just as normal to deliver a week or two before or after.
How To Calculate Pregnancy Weeks And Months Accurately
When do you give birth to a baby? Is it after the completion of nine months or 40 weeks are both the same, or different? If you have just tested positive for pregnancy, you might be doing those calculations already, trying to figure out the due date for your delivery. Dont be surprised if you are coming up with a different date every time you calculate.
MomJunction understands the difficulty in narrowing down on the exact weeks of pregnancy and thereby the due date. In this post, we will tell you how to calculate pregnancy weeks and months. Read on!
Also Check: Can You Have Lasik While Pregnant
If Your Weekly Earnings Vary Or Your Income Changes
To calculate your benefit amount, we use a specific number of your highest paid weeks of employment. We call these your best weeks. The number of best weeks we use is based on the unemployment rate where you live. It could be between 14 and 22 weeks.
If your weekly earnings vary or your income changes, your best weeks can impact your benefit amount.
Gestational Age Vs Fetal Age
Fetal age is separate from gestational age. While the gestational age measures how far a pregnancy has progressed in weeks, fetal age is the growing babys actual age.
Fetal age is counted from the moment of conception. Thus, it is 14 days less than the gestational age, assuming a regular menstrual cycle of 28 days. Health care providers generally measure fetal age through ultrasounds. An ultrasound lets them measure the size of your baby’s head, abdomen, and thigh bone, which together indicate fetal age.
Also Check: Can You Get Lasik While Pregnant
How Do You Calculate Pregnancy Weeks After Ivf
Calculating weeks of pregnancy and the due date is more precise during an IVF than it is during natural conception. This is because the exact date of embryo transfer is known. The insemination or egg retrieval procedure is scheduled before ovulation in IVF, thus making it more accurate.
The IVF due date is calculated by adding 38 weeks to the day the eggs were inseminated.
An alternative calculation is by adding 38 weeks to the date of transfer and subtract the age of embryos from this date. For instance, if it is a three-day embryo transfer, subtract three days, and if it is a four-day embryo transfer, subtract four days .
It, therefore, gives reliable estimated due dates. Also, with progressing pregnancy, the estimated due date could be more accurate based on ultrasound scans.
Theres A New Way To Calculate Your Pregnancy Due Date
When are you due? When you are pregnant, a certain date becomes very important. It is a date you plan things around, and a date that you know will change everything. Traditionally due dates are calculated by last menstrual period. But now, doctors have new guidelines to ensure that women are receiving the most accurate due date possible.
Currently, due dates are calculated by using an estimate based off of a womans last period and the average length of pregnancy, which is a total of 40 weeks. Assuming a regular, 28-day cycle for a woman, ovulation usually occurs around day 14 of the cycle so if fertilization occurs during that window, a woman is considered already two weeks pregnant, as the due date is calculated from day one of the cycle. By the time most women find out they are pregnant when they miss their periods two weeks later, they are already considered a month pregnant.
The problem, of course, is that not every womans cycle operates on a regular 28-day pattern, and ovulation can be unpredictable and change as a result of stress, birth control or sleep deprivation. A woman who has a longer cycle and ovulated later but didnt realize it could actually have a due date thats off by a week hence the reason doctors usually say theres a good two-week cushion for calculating due dates. And lets face it, sometimes women do not recall exactly the date of their last period.
Also Check: Can I Use Vagisil Wash While Pregnant