Time of Conception

[ouchythathurts]

Hi All

Me and my partner have just had our 1st scan with our 1st baby, such an amazing experience!

we wondered if it was possible to tell possible time of conception.

1. first scan yesterday and told we are 12 weeks 2 days pregnant.
2. the 1st day of my last period was the 17th july and this lasted 3 days. - going with this date I would only be reaching 12 weeks tomorrow.

we are just a tad confused because we thought conception happens after a period, but going with the scan this would have been before?

I hope this is clear, please ask any further questions.

thanks :)

[AnnieBrooke]

Doctors give you a medical count for pregnancy, the so-called GA or "gestational age."  The GA count begins on the first day of your period, not at conception.  Given your 12w2d count yesterday, you would have conceived around July 27, and the count projects that your last period began around July 13.  The discrepancy between the 13 and the 17 doesn't mean anything besides that you might ovulate a bit early in your cycle, such as at day 10.

The reason the medical way of counting pregnancy begins on the first day of bleeding of your last period is that ovulation is hidden and can happen at varying times, but a period is a big, fat obvious signal.  Yes, your doctor knows you are not yet pregnant on day 1 of your period, but that is when the count starts just the same.

If you are 12w2d pregnant, you're about 10w2d from conception.

[LadyBeeley]

The doctors go by the growth of the fetus when they determine gestational age. If you read in the other pregnanct groups, and as you will experience for yourself later, as your baby grows, your babys gestatuonal age may change. Its called measuring further or slower than when you would actually be measured according to date of conception. Your baby may be developing at a rate slightly faster than average right now and that could explain the gestational age. My baby happened to measure right on the dot at my 10wk scan. It literally hit every "average" marker. Im just going off the info I have read from this group and experienced from my own appointment.