Due dates

[justonemorethen]

Really confused by these as I have long gaps between my 3 day periods. Great for me...rubbish for getting an accurate due date.

Anyway want to know if it is worth having a scan done privately? By the time the NHS one is confirmed I may be 12/13 weeks. I am 39 and want to do the fold test for DS but that only works to 13 weeks I think? Is that actual weeks or stupid due date weeks with a couple added on?

I think conception took place second week of June. Can help me out as to when the deadline for the nuchal fold test thingy would be in whatever time frame they actually use.

Sorry if this doesn't make sense!

Can't help with dates I'm afraid, but I believe the cut off for Nuchal Fold test is 13+6, if thats any help.

the earlier you have a scan, the more accurate they can be about date of conception/due date, apparently scans are incredibly precise around the 5-7 week timescale, so i'd have one and then you can book your nuchal accordingly.

Thanks. How are they going to decide if I am 13 weeks though? Is it by scan or due dates or something esle.

Ok thanks LS! Will go ahead with the private one I think,just to be sure.

If you assumed you conceived around the 10th June you're 6wks 4days pg approximately at the moment, giving you until the beginning of September to fit in a Nuchal Fold Test. When did you get a positive pregnancy test?

It's hard to know if you don't know when you conceived for sure.

Have you been referred for an early scan on the NHS or just a normal 12 week dating scan? What dates are they working from atm?

They date your pregnancy from the scans btw. They only use your last period as a rough guess until you've been scanned.

Just a 12 week scan on the NHS. I did a PG test last Monday and saw the doctor last Tuesday. She said if I didn't hear anything from the hospital re scan in four weeks she'd chase them up!! Not that reassuring!

How long is your cycle? When was your last period?

I'd definitely get a private early scan when you think you'll be about 8 weeks. Otherwise you could easily miss the chance to have the Nuchal test as that has to be done between and 10 and 13+6 weeks.

They usually try to book the dating/nuchal scan for 12 weeks going by LMP so that there is room for error without it affecting the scan. But if you haven't a clue when you'll be 12 weeks, that doesn't help much.

Brilliant OR. So the date they use after the scan is just conception onwards or ovulation onwards.
I do actually have a DS already and I knew date he was made exactly (bit of a dry spell). He came out to the day (269 days later).
Not that I'm anal about these things.

They date based on the length of the average woman's cycle. So the 40 weeks is inclusive of 14 days before conception (as the average woman ovulates on day 14).

So if you had a scan today and they dated you as 6+4, then it assumes that sperm met egg around June 10th, but the 6wks and 4 days actually start from the end of May as that's when the average woman would have had her last period. Early scans are accurate to within a few days. They will tell you all you need to know.