If an ultrasound says you are 17 weeks and 3 days pregnant is that the day conceived or would it be date plus extra 2 weeks?

An ultrasound that determines a gestational age of 17 weeks and 3 days is referring to the age of the pregnancy from the first day of your last menstrual period (LMP), not the day of conception.

The average menstrual cycle is 28 days, and ovulation typically occurs 14 days before the start of the next period. This means that conception usually occurs about two weeks after the start of your last period.

When calculating the gestational age of a pregnancy, obstetricians and gynecologists add two weeks to the date of your last period to account for the time between ovulation and conception. Therefore, if your ultrasound report indicates that you are 17 weeks and 3 days pregnant, it means that 17 weeks and 3 days have passed since the start of your last period, but you are technically 15 weeks and 3 days pregnant from the estimated date of conception.

Note that gestational age estimates based on ultrasound examinations can vary. It's always best to discuss any questions or concerns regarding your pregnancy timeline with your healthcare provider.