Which is the date of conception on an ultrasound?

There is no such thing as a "date of conception" on an ultrasound. An ultrasound can provide an estimated due date, which is the date that the baby is expected to be born. This date is based on the size of the baby and other factors, but it is not an exact science. The actual date of conception can be difficult to determine, as it depends on when the sperm and egg meet and when the fertilized egg implants in the uterus.