My due date is after scan due date.

[Skinny9741]

Lmp was 27th December which should have made me 8 weeks 5 days but know when i dtd that month and that would of made me 5 weeks and 6 days on day of scan with dd 22nd October. Had a scan on Friday which put me at 8 weeks and 2 days making my dd 5th October. If scan dates are correct i was half way through af and know I didn't have sex on that date. Cant remember when i last dtd before af, it could have been the day before af came but even so, would i be likely to concievr during af? Im more than happy I'm further along than I thought but looking for people who have had similar as I don't want them to put me back 3 weeks on my next scan, then the worrying and anxiety really will kick in.

[KayTee87]

This will help
www.babycenter.com/404_how-is-a-pregnancy-due-date-calculated_10338321.bc

[QforCucumber]

They work it out from the last day of your last period rather than actual conception date so it does sound as though your due date works out right from that.
When you conceive you're actually classed as already approx 2 weeks pregnant (took me ages to get my head around it)

[Skinny9741]

I know that they calculate from lmp but thought that was only until you have a scan which would give you correct dates. I thought the age of the fetus or egg gives you the date you conceived. I have been ttc for 1 year please tell me I'm right and I haven't been doing it wrong all this time

[Skinny9741]

So basically in my head now they either have my dates wrong and egg/fetus/baby is measuring big is that possible? I have been eating alot or I really did concievr during my period, I know that sperm can live for a few days so anything is possible.

[CatsCantFlyFast]

Even the scan dates calculate the start of your pregnancy as 2 weeks before conception.

[katienana]

I was told that at 12 weeks all babies are the same size so that's how they know. I would trust the scan. You can never be sure exactly when you ovulate or when the sperm got to the egg, so the scan is your best bet.

[LouLou030783]

No baby still dates from LMP so u will always be 2 weeks over from conception date, that's why they say you can go either side of ur due date

[MyWey]

No the 2 weeks is always added on even after the scan. Your scan will only likely change your EDD by just a couple of days if you have regular 28ish day cycles.

[CatsCantFlyFast]

You didn't conceive during your period. However all pregnancies are dated back as starting from (approx) 2 weeks before you conceived.

[Ruthiesj]

I am 31 weeks' pregnant, but actually only conceived about 29 weeks ago. It's just how they calculate it.

They haven't always had the technology to use scans and they're not available around the world so in many places they have to stick with lmp; rather than having women in the UK or similar with 38 weeks gestations versus those elsewhere or historically with 40 weeks, they continue to count the times between your period and conception as part of your pregnancy.

[OhShutUpThomas]

It goes from first day of your LMP.

[OhShutUpThomas]

*not last

[DropYourSword]

Pp are right. It's always dated from the first day of your last period, even the scans. It's just the way it's done. So you are due the start of October. Congratulations!

[Skinny9741]

thanks for clarifying can't believe I didn't know this.