help

[lizzie7]

hi, im confused, i had my dating scan last week and it put me at 12 weeks and 2 days, do they add on 2 weeks? am i actually 10 weeks and 2 days? i have read so much on the net and they all say different things, can someone help, thanks

They date it from the first day of your last period so e.g. my last period started on 10th Jan, so i'm 1wk on 17/1, 2 wks on 24/1. Even though you haven't likely concieved in the first two weeks, they still count it from then.

Yes, 12w2d means you likely conceived around 10w2d ago, but remember there is a margin of error:

• Ultrasound measurements date you according to average growth of an embryo
• Measurements are affected by the embryo / fetal position, your bodyweight, sonographer skill etc
• The time between fertilisation and implantation can vary a little (days not weeks); growth kicks off after implantation, before implantation the egg divides but does not grow
• And of course sperm can live 5d or so before fertilising an egg

thank you :) xx

Thank you for asking this, I was so confused by it!
I find it remarkable that you could be pregnant for 2 weeks 'officially' without even having had sex...

just looked at a post a sonographer put on, and hes a professional, and by the looks of that iam indeed 12 weeks and 2 days!! there is 5 days either way it could be out!! see how confused iam haha, i will ask my midwife best way, because what is the point of a dating scan if they add on 2 weeks, it would be the same as from your last period otherwise Confused:

The reason for dating you from you last period is because (in general) people are more likely to know when their last period was than when they conceived. Unless of course you had IVF or similar, all you know is when sperm was deposited and when you may have ovulated... Even with IVF the start of your pg will officially be before fertilisation. Also, an ave pregnancy lasts around 40 weeks from your last period. So yes weeks 1 and 2 of officially 'being pg' could be while you are a virgin, it's a bit odd if you think about pg beginning with conception but if you think of it as when your egg began to be made ready to be released it makes more sense. But just get used to it as your antenatal care will all be based on these dates.

thank you :) xx

It is very confusing in the beginning when you aren't very pregnant but a dating scan is still needed because adding two weeks doesn't take everyone back to the date of LMP only those that have regular 28 day cycles. My dating scan changed my due date because I'm rubbish at keeping track of dates and had given the wrong date for my LMP others may just have longer cycles, a friend of mine had an implantation bleed that she thought was a period so was actually 4 weeks further on than she thought.

Anyway the more weeks you get behind you the less it seems to matter, it really bothered me for the first few weeks, now I'd just quite like someone to add another two weeks on so I could start sleeping on my front again a bit sooner