How do calculate conception date

Therefore, the formula to estimate the conception date based on the LMP:. Let's take Anne. She is 11 weeks pregnant, and still doesn't know her conception day. The first day of her last period LMP was 11 June , and typically, her cycle lasts for 31 days still in range, between As mentioned before, we can assume that her ovulation began around 17 days after her LMP, on 28 June She conceived around her ovulation date as a woman's egg can last up to 24 hours , on 28 June However, instead of all this counting, she used our pregnancy conception calculator.

Next up is Maggie. She just came back from the doctor, who told her that the due date is on 19 September Now, she has one question: 'what day did I conceive? You don't have to do the calculations by hand! Just put the numbers into our conception date calculator based on the due date. It can also work as a pregnancy week calculator, giving you an estimated week of pregnancy and the first day of your last period.

Now, to ensure that both the mother and child are healthy during and after pregnancy, both Anne and Maggie should control their pregnancy weight gain.

Yes, of course. So, when does conception happen? 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. However, with our conception calendar calculator, you can make an estimated guess!

You might be pregnant! Now it's time to take a pregnancy test and make an appointment with a doctor. Congratulations again! A new journey in your life begins. Although you can't know everything, and a lot of things might change, you can predict some things, such as your child's height , or even their blood type! We try our best to make our Omni Calculators as precise and reliable as possible.

However, this tool can never replace a professional doctor's assessment. If any health condition bothers you, consult a physician. No conception date calculator is completely accurate , as they are estimating the date it occurred. The most accurate measure is to take an ultrasound and have a professional estimate the age of your baby for you.

This service, however, will likely cost you though, so use best use an online calculator. Moderate drinking does not impact fertility or the risk of miscarriage in regular pregnancy, a number of studies have found. However, if you are trying for a baby using IVF, both partners should not consume any alcohol.

The woman should always stop drinking as soon as she finds out she is pregnant. Conception occurs in the fallopian tubes , more specifically the ampulla, where the oviduct curves around the ovary. The egg releases large amounts of progesterone here, which the sperm are attracted to. This is how the sperm know how to reach the egg.

You can estimate the day you conceived on as soon as you know you have missed your period. This is also the best day to take a pregnancy test. Use Omni Calculator to work out your conception date quickly and easily. To find your conception date, you will have to perform some calculations to estimate it. Twins When a twin pregnancy is the result of in vitro fertilization determination of gestational age should be made from the date of embryo transfer. Otherwise " The table below shows the average age of infants delivered in the United States according to the number of fetuses being carried plurality [29].

The earlier age at delivery of multiple gestations is a reflection of the increased incidence of preterm labor and obstetric intervention for complications such as preeclampsia, abruptio placentae, fetal growth restriction, and increased risk for stillbirth that occurs as the number of fetuses increases [].

The tendency for multiple gestations to be delivered earlier than singleton pregnancies should not be interpreted that multiples should be assigned an earlier estimated due date.

Am J Obstet Gynecol ; PMID 2. PMID 3. PMID 4. Clinical management guidelines for obstetricians-gynecologists. Number 55, September replaces practice pattern number 6, October Management of Postterm Pregnancy. Obstet Gynecol. PMID 5. JAMA ; PMID 6. Comparison of pregnancy dating by last menstrual period, ultrasound scanning, and their combination.

Am J Obstet Gynecol. PMID 7. Birth weight from pregnancies dated by ultrasonography in a multicultural British population. Sep 4 ; PMID 8.

Ultrasonography in Pregnancy. American College of Obstetricians and Gynecologists. Conceptional age, menstrual age, and ultrasound age: a second-trimester comparison of pregnancies of known conception date with pregnancies dated from the last menstrual period.

PMID: Trauma in pregnancy. Emerg Med Clin North Am. Hay DL, Lopata A. Chorionic gonadotropin secretion by human embryos in vitro. J Clin Endocrinol Metab. Wilcox AJ, et al. Time of implantation of the conceptus and loss of pregnancy. N Engl J Med. Lohstroh P, et al. Your fundal height, which is the measurement from your pubic bone to the top of your uterus, is checked by your practitioner at each prenatal visit and helps confirm your 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 or even the week or month!

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.

Yes, your due date can change. It may be that you have irregular periods and your early ultrasound dating was off, or that your first ultrasound was in the second trimester. It could also be because your fundal height is abnormal, or your levels of alpha-fetoprotein AFP , a protein made by the baby, are outside the usual range.

Talk to your practitioner if you have any questions or concerns. The educational health content on What To Expect is reviewed by our medical review board and team of experts to be up-to-date and in line with the latest evidence-based medical information and accepted health guidelines, including the medically reviewed What to Expect books by Heidi Murkoff. This educational content is not medical or diagnostic advice.

Use of this site is subject to our terms of use and privacy policy. Registry Builder New. Due Date Calculator When is your baby due? Use this pregnancy calculator to find your due date based on the date of your last menstrual period, conception date, IVF 3-day or 5-day transfer date or date of your last ultrasound. Calculation Method.