Doctor insights on:
Calculate Date Conception
See your OB: Not a good situation, your OB can do an ultrasound for dating purposes and blood tests can be done on the baby after delivery and the 2 guys to determine who is the father if necessary, so see your OB on monday. ...Read more
Depends: Conception usually occurs about 14 days prior to the onset of the next expected period. If the periods are 28 days apart, conception occurs around day 14. If the periods are 32 days apart, then conception occurs on day 18 (32 minus 14 = 18) etc, etc. ...Read more
38 weeks earlier: If your periods were every 28 days, your OB can help you figure it out that is part of your ob's job. ...Read more
Can you accurately calculate date of conception if you have irregular cycles? Early US & 6w 1d said EDD was 4/16. 14 weeks later @ 20w EDD said 4/13.
Use an app: There are many apps available where you can enter your due date and get the date of conception (look for "pregnancy wheel". Alternatively, if you know what week you are today, convert the weeks into days (for instance, 18 weeks and 3 days equals 129 days), then subtract 14 days (129-14=115), then count back that number of days. This will give you your conception date. ...Read more
Naegle's rule: By universal convention, a pregnancy is dated in weeks since the date of the last menstrual period. The due date is 40 weeks from the first day of the last period or approximately 38 weeks after date of conception. Your OB can give you a better answer after your first early ultrasound around 8 weeks.... ...Read more
Your OB can: Show you on an OB wheel you are due 38 weeks from your conception date if you were having 28 day cycles. ...Read more
I have an irregular menestration, 2-4months between periods. How do I calculate my conception date?
Ultrasound: When you have an irregular menstrual cycle, it is very difficult to pinpoint your due date. Even if you are irregular, we would date your pregnancy based on the first day of your last menstrual period (lmp) unless a sonogram in the first trimester disagrees. In my practice, I would do a sonogram to establish the dates around 9 weeks or so based on your stated lmp. ...Read more
If you can get pregnant within the 2 weeks of gestational age how do you calculate the conception date if transvaginal u/s on 6/11 dated me at 6wks 3day?
May 11th: The conception date based on that ultrasound is may 11th with a range of may 8th through may 14th. I hope that's helpful. ...Read more
My last period what may 3 and I am pregnant my cycles come around the same time each month in april it came around the 5th. I have been trying to calculate my conception date but don't quite understand how to. At an 8wk check up I had an ultrasound and sh
2/7/13: On reg periods, which it sounds like you have, you can expect to ovulate about 2 weeks before your next period starts. ...Read more
Unsure: Because the majority of women do not know when they conceived; many can give a good report of when their last period was. ...Read more
Naegele's Rule: The naegele's rule estimates the expected date of delivery (edd) by adding one year, subtracting three months, and adding seven days to the first day of a woman's last menstrual period (lmp). Just apply in reverse: last menstrual period was about 2/20/13: conception two weeks later. ...Read more
Am preg. My last period is 4/13-4/18. Am trying to calculate when I get preg. It so confusing. When do I ovulate and conception or conceived happen?
How are conception dates calculated if I don't have a regular 28 day cycle but had a transvaginal u/s done 6/11 dating me 6 weeks 3 days?
When is pregnancy calculated first day of last period or conception because my LMP is 9-8 40 weeks from that would give me a due date of 6/15?
Early ultrasound: Assuming that you aren't using in vitro fertilization, which of course gives the doctor the exact date of conception. Most women date a pregnancy by having a first trimester ultrasound. Ultrasounds performed between seven and nine weeks just station provide the most accurate measurements for dating a pregnancy. As the pregnancy progresses the ability to date accurately diminishes. ...Read more
January 27, 2013: Due date is about 38 weeks after conception date. ...Read more
Yes: Ultrasound dating is most accurate early in the pregnancy using the crown-rump length (crl) of the small fetus. The measurement can be done starting around 6 weeks. While crl can be used for dating until 12 weeks, it is most accurate during 6-8 weeks when the accepted error is only about 3 days from actual date. ...Read more
EDC: About June 26, 2014.Get a more detailed answer ›
July 18: July 18-plus or minusGet a more detailed answer ›
May 3rd: The approximate conception date would be may 3, 2012. ...Read more
5/9/13: Your average conception date would be 5/9/13, give or take a few days on either side. Hope that helps! ...Read more