Last Updated on September 16, 2022
If your due date is December 19, but you did not conceive before that date, you might be wondering: when did I conceive? You are likely to have your first ultrasound scan around two months into your pregnancy. The scan is mainly done to figure out your due date but may also be used to determine the gestational age of your baby. This test can also tell you when you conceived, based on the baby’s growth and the uterus.
Calculating your due date
Using the date of your last menstrual cycle to calculate your due date is a good way to determine when you should expect a baby. Unfortunately, the conception date can be off by a few days. Many women aren’t even sure when they conceived! In fact, sperm can survive in the reproductive tract for five days after sex. It may be difficult to predict your due date, but the good news is that pregnancy calculators are now available that help women get an idea of when they’re most likely to conceive.
The easiest way to calculate your due date is by using the first day of your last menstrual period. Add seven days to this number and multiply it by two. If you had a period on March 20, you’d calculate your due date as March 27. Another method is to add forty weeks to the date of your last menstrual cycle, which will give you an approximate date of when you’ll be due.
If you are unsure, you can use the size of your uterus to estimate your due date. After 12 weeks of pregnancy, your doctor or midwife will be able to feel the top of your uterus above your pelvis. At 18 weeks, the top of your uterus will be at the height of your belly button. At 20 weeks, the top of your uterus will be roughly equal to the height of your pubic bone.
In the case of irregular menstrual cycles, it is important to consider that you may not conceive at the exact same time. If you suspect that you are conceiving, an ultrasound will help confirm your due date. Ultrasounds are not perfect, but can help you determine your exact due date. By getting your ultrasound, you can also learn more about your pregnancy and its gestational age.
Another way to determine your due date is by using a calculator. Most medical professionals will begin by asking you when your last menstrual period was. Depending on the length of your cycle, your medical team will be able to estimate your due date based on a simple equation. For example, a woman may be due two months before her last menstrual period. With this information, your doctor can help you plan your pregnancy accordingly.
Because most pregnancies last approximately 38 weeks from conception, you’ll want to calculate your due date as soon as possible. However, this method only works if you know when your last menstrual period was. Counting backwards from your last menstruation, you’ll have an estimated date that’s two weeks earlier or later. This is the best way to determine your due date.
Estimating due date with an ultrasound
During the first trimester, an ultrasound is not very accurate at predicting your due date. It can be off by up to 3 weeks. However, as your pregnancy continues, an ultrasound can be more reliable as an early indication of the baby’s development. Generally, an ultrasound in the second trimester is much more accurate. Your doctor will give you an accurate due date based on the latest measurements. However, an early ultrasound can give you a false due date.
Another reliable way to estimate your due date is to measure the size of your uterus. At twelve or eighteen weeks of pregnancy, your doctor or midwife will be able to feel the top of your uterus above your pelvis. By 20 weeks of pregnancy, the top of your uterus will be the same height as the top of your belly button. This way, your ultrasound doctor will be able to see if your baby is still in there and whether you’re ready for delivery.
Using an ultrasound, your doctor can estimate your due date and compare it to your last period. Although your last period is a reliable indicator of ovulation, the ultrasound result will often be different. In some cases, your ovulation might be earlier than expected and change your due date. If this happens to you, your health care provider will change your estimated due date. So, your ultrasound will be more accurate than your last menstrual period.
Pregnancy outcomes can improve if you have accurate information on your estimated due date. Accurate dating is an important public health and research imperative. In general, your doctor should determine your EDD based on your last menstrual period and your first accurate ultrasound examination. This date should be documented in your medical record. Only in rare cases should your due date be adjusted. As long as the change is documented and discussed with the patient, it is a reliable way to determine your baby’s due date.
It is important to note that the most accurate way to estimate your due date is to undergo an ultrasound in the first trimester, before the second trimester. According to the American College of Obstetricians and Gynecologists, an ultrasound should be performed between six and eight weeks, six days and is considered accurate at this gestational stage. This measurement may be off by more than three weeks from your expected due date.
Due date estimation is more accurate if it is done early. The earlier the scan is performed, the more accurate the estimate. Dating from the last month is less accurate. As a result, a doctor’s or midwife will often rely on the ultrasound measurement rather than relying on the date you know. It is also important to consider your menstrual cycle, as it can impact the length of your pregnancy.
Changing due date based on inaccurate results
Changing due date based on inaccurate test results is not a good idea. An accurate date is not only a better decision for you, it’s also a better choice for the baby. With accurate due date information, a doctor can better plan interventions to prevent preterm birth and increase the chances of delivery at a later date. Also, accurate dates help prevent the risk of NICU admission for premature babies.
The most accurate way to calculate your due date is to get an ultrasound in the first trimester. If you’re having trouble with your periods or want to change your due date, an ultrasound during the first trimester can be a good option. Some early pregnancy symptoms to look for include cramping, headaches, mood fluctuations, and metallic taste in the mouth. These early signs of pregnancy are often the culprits when due date changes.
The American College of Obstetricians and Gynecologists (ACOG) recommends that women not change their due date in the third trimester, unless it’s clearly necessary. But there are other times when changing your due date is a good idea. The doctor may change your due date based on inaccurate results. If you’ve already had an ultrasound, consider scheduling a follow-up one to see how your baby is developing. This will also give your doctor the chance to confirm that your pregnancy is progressing as expected.
The American College of Obstetricians and Gynecologists (ACOG) recommends an early first-trimester ultrasound. The new recommendation allows doctors to determine a woman’s due date more accurately than by using a woman’s menstrual cycle alone. Changing due date based on inaccurate results may be a good option if you are concerned about inaccuracy of ultrasound results.
About The Author
Mindy Vu is a part time shoe model and professional mum. She loves to cook and has been proclaimed the best cook in the world by her friends and family. She adores her pet dog Twinkie, and is happily married to her books.