Ultrasound accuracy dating sundaytimes co za dating
Having an ultrasound in the first trimester of pregnancy can be a thrilling experience. Bear in mind that you may need a second ultrasound before you know for certain if all is well.It's wonderful to see a little blob with a heartbeat that will become your baby. If you are unsure of the first day of your last period you will be offered a dating ultrasound when you are between 10 and 14 weeks pregnant.If you have an irregular cycle, or if you've recently been taking the contraceptive pill, working out the date from your LMP isn't a very accurate method.Ultrasounds are more accurate than using the LMP and, if the ultrasound date differs from your period dates, the ultrasound date will be used.
If you do know the conception date, this is classed as day 14 and not day one.Could the birth control not have worked in Jan, the embryo lived through the withdrawal bleeding, and the fetus has continued to measure small throughout the pregnancy? According to this period date, the most likely date of conception would be around 14 days after the period, that is around the 19th of February.Ultrasound has intrinsic error of upto maximum 5 - 7 days, so the probable dates of sex would have been a week before or after the 19th of February, but in NO WAY as early as January 18th.But ultrasounds can also lift the lid on a few worries you might be having. The main reason for the ultrasound is to work out how many weeks pregnant you are, and to estimate your due date.The length of your pregnancy is calculated from the first day of your last menstrual period (LMP), even though you don't actually conceive until 14 days after your LMP, and later than this if your cycle is longer than 28 days.
Other ultrasounds at 19, 21, and 27 weeks all gave EDD of 11/12. Totally 6 ultrasounds have all given you the same EDD - 11/12.