For a woman with a regular period, conception typically occurs about 11-21 days after the first day of the last period.
Most women do not know the exact date of conception because it can be challenging to know exactly when ovulation occurs.
However, if all is going well in this pregnancy, your particular hospital may not offer the scan.
Ask your GP if you want to have one anyway for extra reassurance, as she may be able to refer you.
Since the exact date of conception is almost never known, the first day of the last menstrual period is used to measure how old the baby is.
The date of the first documented positive pregnancy test and the beta-human chorionic gonadotropin (b HCG) level may help ascertain the minimum gestational age.
In women who conceived following assisted reproduction techniques, the date of embryo transfer is known and may date the pregnancy accurately.
You may have calculated the length of your pregnancy from the first day of your last menstrual period (LMP).
However, conception doesn't actually occur until around 14 days after your LMP, or later if your cycle is longer than 28 days. The rhetoric of "natural" in natural childbirth: childbearing women's perspectives on prolonged pregnancy and induction of labour.