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Pregnancy

Talk about every stage of pregnancy, from early symptoms to preparing for birth.

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Original poster

I REALLY STILL DONT UNDERSTAND?

70 replies

sparklingreactions · 14/01/2009 15:39

okay i have posted before about being confused about scan dates anyone that can clear this up 4 me id b so grateful xx

I know scans are dated from your lmp, so does conceptions occur about 2 weeks after they think you had a period? how is a pregnancy counted is it counted from implantation and then two weeks back to where your period should have been? or from when they think you concieved and the two weeks back to your period at which week of pregnancy does the egg implant in the uterus? would this mean your period was two weeks before this time? someone pleaseeee explain xxxxxxxxxxxxxxxxxxxxxxxx

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NAB3lovelychildren · 14/01/2009 15:40

Is there a reason you are stressing about this?

wasabipeanut · 14/01/2009 15:43

Pregnancy is dated from LMP because (I believe) ov times vary so much. There is then an assumption that it happens CD14 of cycle.

It's very difficult. The bit that baffles me is that this doesn't allow for implantation time - that can take up to 10 days I believe.

beanieb · 14/01/2009 15:44

Actual implantation occurs something like 7-10 days after you ovulate. Some people consider conception to be fertilization, some believe it to be implantation.

For the purposes of dating a pregnancy doctors always count from the first day of your last period, but medically it is very rare to get pregnant on the first day of your period.

I think that's the case.

Northernlurker · 14/01/2009 15:44

Your lmp is considered the last time that they know you weren't pregnant! When your period is one day late (assuming BFP) you are counted as being 4 weeks and 1 day - because in theory you could have got pregnant at any point in your cycle. Most likely (assuming 28 day cycle) your egg was only fertilised 14 days previously so you are technically only two weeks into pregnancy but it's counted as 4 because we don't have cctv in our wombs When you have a scan they are counting from the first day of your lmp as well so say 9 weeks 5 days is 9 weeks etc from lmp not from when you think you conceived. That at least is my understanding and as I've had three children i'll be very embarassed if i'm wrong!

youknownothingofthecrunch · 14/01/2009 15:46

That's pretty much it. Your dates are done from the first day of your lmp, then if your dates are done by scan your "day one" is counted as 2 weeks earlier than the date of conception.

This is because most people ovulate around day 14 and scans are a relatively new thing in the whole "people having babies" history, and pregnancy is timed from the date of your LMP.

Any clearer?

Original poster

sparklingreactions · 14/01/2009 15:48

so if they said i was 9 weeks from my lmp i would be about 7 weeks from conception? does conception occur when the sperm meets the egg or when the egg is implanted? i have abit of ocd i like to know how evrything works sorry xxx

OP posts:

Northernlurker · 14/01/2009 15:51

What is conception is a bit of a thorny moral and ethical issue tbh - My opinion is that sperm meeting egg has the potential to become a pregnancy but if that fertilised egg doesn't burrow in properly then there can be no baby - so I think conception starts at implantation - but others would disagree with me I think.

NorktasticNinja · 14/01/2009 15:51

Conception is when sperm meets egg (which can be several days after sex).

NorktasticNinja · 14/01/2009 15:53

Northern x rather than pointed disagreement!

Original poster

sparklingreactions · 14/01/2009 15:54

if i give my dates will someone help me understand when i concieved? can anyone help? xxx

OP posts:

NorktasticNinja · 14/01/2009 15:56

sparklingreactions - calm down petal. Give me the dates and I'll give you a hand.

Original poster

sparklingreactions · 14/01/2009 16:00

okay right i had an early scan it showed i was 8 weeks and my lmp was june 4th however my period was just over a week before ths date so i dont really understand when i concieved? 2 weeks from the 4th showed the 18th and i know i had sex on the 16th i had another scan thet showed i was 13+2 this would make me 4 days less pregnant that the first scan however they took my due date of the 15th of march from this date. i had another scan that shoed 21 weeks which tied in to the first scan but obv they kept the due date from the dating scan any idea im jus abit confused as my period didnt tie in xxxxxxxxxxxx thankyou so much xxxx

OP posts:

Original poster

sparklingreactions · 14/01/2009 16:11

bump

OP posts:

NorktasticNinja · 14/01/2009 16:13

Conception is impossible to pin point precisely, however you can be pretty much 100% certain that you conceived from the sex you had on the 16th. Conception two days after sex would be pretty standard - sperm can live internally for 3 - 4 days. Conception is most likely when the sperm ready and waiting when the egg is released.

In the cycle in which you conceived you ovulated on around cycle day 21 rather than on the standard/assumed day 14 of your cycle. When they take a dating scan they look at the development (which starts at conception), pin point a date and then add two weeks to give an assumed date of LMP. This date does not have to have anything to do with when your period actually was.

Each baby develops at a different rate and scans after 12 weeks are much less accurate at dating than those before 12 weeks. That is why they kept the original EDD from your dating scan.

Do you understand now?

Original poster

sparklingreactions · 14/01/2009 16:19

thankyou so much thats made it alot clearer but if i ovulated around day 21 that would mean i ovulated on the 15th and i had sex on the 16th could i still have concieved here if my scan showed the conception on the 18th sorry 4 being a pain in the arse xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

OP posts:

NorktasticNinja · 14/01/2009 16:22

"early scan it showed i was 8 weeks and my lmp was june 4th however my period was just over a week before ths date" - you didn't give the date of your actual LMP making it impossible to work it out precisely

If 21 days after actual last LMP was the 15th then you ovulated on day 24 of the cycle in which you conceived (presuming that the 16th was the only time you had sex around the 18th).

NorktasticNinja · 14/01/2009 16:24

ovulated conceived (although it probably happened on the same day).

Original poster

sparklingreactions · 14/01/2009 16:25

yeah i had sex on the 15th well kinda in betwen the 15th an 16th lol only time i had sex before this date was the day before my period and the dates wouldnt be right for that would they xxx

OP posts:

popcal · 14/01/2009 16:25

Do you have a normal 28 day cycle? Do you know if you ovulate late in your cycle? if so this can affect your dates.

Original poster

sparklingreactions · 14/01/2009 16:26

my period was the 25th of may xxx

OP posts:

NorktasticNinja · 14/01/2009 16:27

OK so the sex on the 15th / 16th was the sex from which you conceived. I can't tell you which sperm it was though, lets just call him The Winner

You have to stop worrying about this now!

Original poster

sparklingreactions · 14/01/2009 16:30

ill put all my dates up xxxx

sex 24th may 08

period 25th may 08

sex 16th june 08

1st scan 8 weeks (30/7/08)

2nd scan 13+2 (9/9/08)

3rd scan 21 weeks edd not changed (28/10/08)

due date 15 march 09 (taken from 2nd scan)

OP posts:

Original poster

sparklingreactions · 14/01/2009 16:31

hah sorry just thought i was confusing you abit so i put my dates up feel free to check haha xxxxxxxxxxxxxxx

OP posts:

bronze · 14/01/2009 16:31

may?
you would be about 33 weeks by now. By this stage any lmp dates are kind of by the by as they would go by dates from your scan anyway.

But I'm still confused as earlier you say your lmp was 4th june

bronze · 14/01/2009 16:32

sorry x post took me a whiel to press send

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