calculating the weeks, confused!

[nightowlmostly]

Now, I know that the doctor will date the pregnancy from the day of your last period starting, but when I'm looking on babycentre at the development 'this week' I'm getting confused. Even though I've put my due date in based on the date the doctors use, it tells me I'm 7+4 when in reality I could only be 5+4.

This isn't really that important I guess, it's just that when looking for info on how things are developing this week, it must be two weeks out, surely? Will I get a dating scan to confirm the actual dates or will it stay as it is?

Sorry, this is probably a stupid question!

Not a stupid question at all it's one of those random pregnancy things, when you are classed as 7 weeks pregnant you've actually only been pregnant for 5 weeks. They date it from the date of your last period which is usually 2 weeks before you actually became pregnant. They'll adjust it at your 12 week scan if needed.

Thanks, I just want to be looking at the right info, babycentre are emailing me with 'you are 7 weeks' and I think, yes but not really!

You do still count as 7 weeks pregnant though, so if you are looking up those week by week descriptions, you'd look at the weeks ifkwim..

Oh, so they take that into account do they? That would be sensible I guess.