Signs are that it will be an early baby (1/2way engaged, some mucus plug loss etc).My EDD via my LMP is at 25/09/09..my first scan at 11wks, gave me a EDD of 18/09/09..my NT scan 2 weeks later, had my due date at 22/09/09, and my 18-22 wk scan, done at 20 wks, had me at 23/09/09...I can safely say that my bubs is due anytime between the 18th and 25th of Sept....In the end - only the baby can determine the true due date, and it is not they that get it wrong, but the system.I read somewhere that only 5% of babies come on their actual due date!!(we are going with my LNMP date for 14th July, the scan says 16th I think) Oh and I'm measuring 2-3 weeks further along this time, too!
DD1 was "due" on Feb 26th but arrived 15 days earlier on Feb 11th. It really is hit and miss..just an estimate as others have said...been 'prepared' since about 37 weeks...here i am, 40 weeks today and no sign of baby....take it as gospel, bubs could come 10-14 days after your EDD......thats all it is..a estimated due date... My dating scan with this bub at 8 weeks was really inaccurate, it gave me an EDD of 28/8/09 when by my dates I should have been due around 22/8/09.
I would offer early scans especially when you don't know your dates but when looking at baby's actual birth date to the early scan there is often weeks difference.
I think they come when they come some earlier some later.
between 4 and 10 weeks the accuracy is only a day or two out at most after about 12 weeks it can be out by up to a week.
I was told this by my sonographer 2 weeks ago coz my bub was measuring a week and a half ahead of schedule The scans really assess the conception date rather than the arrival date as the baby can be born either side of the "due date" as others have said.
I can't remember what my dating scan said with DD, who arrived at 38 weeks. I think that when it comes to dates you need to keep in mind that it is an *estimated* due date.