No, that is just an old wives' tale.
From the date of conception to date of birth is usually 23 days. If you mean from when they go into labor, it could take a day.
Conception dates do not depend on the length of your period. Your due date is based on the first day of your last period. Your baby was actually conceived about 2 weeks later.
A conception date can never be 100% accurate
The approximate date of conception was June 25th
The approximate date of conception was September 10th
Your date of conception will be approximately 15 Mach.
For about the first 10-12 weeks all babies grow at about the same rate so term date can be calculated fairly accurately, you then count back 38 weeks for the date of conception. After 12 weeks babies may not all grow at the same rate so it becomes less accurate.
EDD is ESTIMATED. If done by scan is 38 weeks from conception. An EDD is based on the LMP (last menstrual period) and not the date of conception. The ultrasound measurements are comparing the baby to the expected size of other babies at the same gestational age. The earlier the ultrasound is done in the pregnancy, the more accurate it will be. Hope this helps! Dr. B.
The approximate date of conception was May 11th 2009.
The approximate date of conception was August 15th
The approximate date of conception was May 16 2009.
The approximate date of conception was June 6th 2008