Due date???

my best friend found out she was pregnant a little bit after i did. her last period was dec 5 ended, then got another on the 10th that ended on the 14th. that one was very light, not like a reg period. then she got a positive on jan 15 or 16th. she is unsure of her dates because of this extra period, and the doctors are confusing her about her dates because of an ultrasound at supossedly 9 weeks, when she thought she was 10 or 11 weeks. the ulrasound was done feb 29th and they told her she was only 9 weeks at that ultrasound. they told her she was due oct 5th but its not adding up..anyone with some help as far as conceptuion date goes, and why these dates are coming out like this, plz answer...we do not want to use a calendar, becasue we have tried already. we are confused about this extra period, and would like some help figuring this out! thx alot in advance..ten points for the best answer!!

Due date???
it doesn't add up because my lmp was december 25th and i'm due on september 30th. however they are probably calculating her due date by the babies size and not by the dates since there were so many and it's likely that all three weren't technically "periods" also she possibly doesn't ovulate like most women assume they do. she should be getting another ultrasound soon huh? probably within the next 4-6 weeks so they'll probably date the pregnancy again and maybe things will work out but i would just go by what the ultrasound says.
Reply:early u/s are extremely accurate. once you are later in pregnancy is when they very up to 2 weeks. but early on they are usually accurate.
Reply:Ultrsounds are that way. When I first found out that I was pregnant with my daughter in 2005 I was told that my due date would be the beginning of July 2006. At my first appointment I should have been 11 weeks according to when my last period was. They did an ultrasound and I measured at only 8 weeks. So my new due date was the end of July. I ended up having my daughter early due to medical problems with me and she should have been four weeks early according to the ultrasound but she weighed almost 8lbs. My advice is to wait for the second ultrasound and see what it says but don't always trust them.
Reply:my lmp was 13th aug so i should of concived around the 27th aug and due 20th may 08


but my ultrasound said i concieved 4th sept and due 27th may at had scan at 12 weeks, it was the same at the 20 week scan too.





the ultrasound is more accurate than her period xxx
Reply:I would go with the ultrasound reading,they are REALLY accurate. I knew how far along i was by all my ultrasounds and the babies came pretty close to the dates. Good Luck and happy pregnancy! : )
Reply:The best thing to do is wait until the second ultra sound that one will be a bit more accurate
Reply:This link explains dating!





http://www.askdramy.com/dating.html
Reply:The ultrasound will be the most accurate. Pregnancy dating by periods assumes a woman becomes pregnant on day 14 of a normal 28 day cycle. Which doesnt add up for everyone! Shes probably ovulated and therefore become pregnant late in her cycle. I was the 10 days less pregnant(by ultrasound) then I thought I should be (using period dates) with my first. She probably fell pregnant very early in January judging by the ultrasound dating.
Reply:Mine was like that also, ultrasounds can give or take about 2 weeks....there not 1000000% on the actuall due date