due date confusion

[twinkletwinkle04]

I went for a scan yesterday believing I was 8 week plus 4 from last period dating. Lady who done my scan said the baby is measuring 12.2mm which dates at 7wks 4. I had unprotected sex once and I'm really not happy about dating behind as my last child was premature at 36wks. My concern is I had a positive pregnancy test two days before my missed period using a crappy test. (would have been 2wks 6 days) which I thought was impossible. I'm just trying to figure out if my dates are more right than the doctors? My basis being the extremely early test if theyre right. They won't listen to me so I'm trying on here for advice x

[PenguinsandtheTantrumofDoom]

In most areas, regardless of your views they will date on scan measurements and not your information. I had this too, but was put forward.

What is your concern about the prematurity? That treatment might be affected by dates?

[twinkletwinkle04]

Yes that and curiosity about the pregnancy test. I feel like I was spoken to like I was stupid today over it.

[twinkletwinkle04]

I was determined I was further on with my son and the put the date back due to scans. He was completely healthy but I was treated extremely high risk during labour when he was my second biggest of 4. I don't want it to happen again.

[addictedtosugar]

Was a that an early scan, or your dating scan?? That early in pregnancy, a tiny difference in measurement makes a big difference. Can you imagine measuring a moving blob to greater than a mm accuracy, when you are measuring through skin and muscle? If you have a further dating scan in a month, you may well find your dates and scan dates match up a little more closely.

[fanjodisfunction]

sperm can last for a few days, so your dates of sex may not be the actual date of conception.

pregnancy is is generally forty weeks, so they can only really figure out the care etc by taking measurements, its not exact really but it gives a there's about age of the baby.

[fanjodisfunction]

I'm sure due to your pregnancy history they will take good care of you and the baby, you may find the dates change again at you next scan.

[Roseybee10]

Dd1 measured 6 weeks at 7 weeks, then 9+3 at 10+1 and by 13 weeks she measured 12+6. You could find measurements marry up by 12 week scan x

[PenguinsandtheTantrumofDoom]

Oh yes, that is a very good point. Early scans are often 'out'. It might revert at 12 weeks.

[LumpyCustard69]

They moved my due dates about with my first, despite me knowing when my last period was, and when I'd had sex. They moved my date gradually from 27th May, to 11th June, and then let me go 2 weeks overdue. My dd was 11lb when born, and had erbes palsy and shoulder distocia. There were 10 people in the room when I gave birth, and dd was taken to scbu after I'd spent all of 2 minutes with her. I was not (and still am not) happy about how I was basically told I was wrong and head patted as it was my first pregnancy.

If I were you, I would suck it up, because they won't listen to you in my experience, but find an excuse to go in for a scan when they say you're around 29/30/31 weeks. That way, if baby is closer to your dates, they can re jig their plans for you.

[LumpyCustard69]

*2 weeks over past THEIR dates therefore 3/4 weeks over mine (depending on how long after sex conception took place)

[twinkletwinkle04]

I know dates are sometimes out but a full week considering the pregnancy test is a bit much. I never questioned my youngest being dated wrong as I never knew for sure until he was born. That's more my question of the pregnancy test coming up 8 days early

[Roseybee10]

Mine was a full week out at just over 7 weeks so it's not impossible.
Do u know when you ovulated? You could have ovulated 4 days after having sex then it could have been a late implanter.

[mrschatty]

Mine was measuring 9+1 I was sure I was 9+6 apparently it's normal to measure a week put don't worry :)

[twinkletwinkle04]

I should have ovulated between the first and fourth of may. I had sex on the fourth. By the scan I got pregnant on the 9th of may so I know it's possible for sperm to survive that long but if that's when I got pregnant surely the test wouldn't of been positive until at least 5 days after I missed my period?

[Roseybee10]

Maybe that's when baby implanted?

Remember that scans are only an average and babies vary greatly.

My first daughter I got a very strong positive two days after period was due and a 2-3 weeks on a cbd. We did the deed 3 days and 1 day before ovulation as we were trying. I had a 28 days cycle with a 12 day luteal phase and still got a strong positive then.
She then measured behind til 12 weeks but was then 8lbs 2 at birth.

Dd2 we did the deed the day of ovulation (not trying, just a one off). Still a 12 day luteal phase. Much fainter bfp at 2 days after period due and only a 1-2 on cbd.
By 8 weeks she was measuring spot on but by 12 weeks she was measuring 3 days behind my dates.
She then continued to measure slightly behind and was only 6lbs 14 at birth.

Logically, dd2 should have been measuring behind at 8 weeks as she should have implanted later than dd1. I got a stronger positive with dd1 so logically she should have been measuring more ahead than dd2 at the same gestation.

What I'm trying to say is there is no point in getting hung up about every little reason why you think their dates are wrong. It's likely baby will either catch up or maybe just measure a bit small throughout. A few days won't make much difference to your due date and essentially the baby will come when it's ready anyway, whatever they or you make the due date to be.

Pregnancy tests can pick up a pregnancy up to 5 days before a missed period so it's not unusual at all to get a positive test when you got one

[happygojo]

At my 12 week scan, I was put a week ahead, which would mean I conceived on a Monday when still on my period BEFORE we had agreed to start TTC again. Since then baby has been measuring a few days smaller, but nothing to worry about.

Babies grow at different rates, just as children grow at different rates, also it is likely that at 12 weeks you will be put forward again. I wouldn't worry at this early stage.

[happygojo]

Ostrich that's a tad harsh and unnecessary. It's ok for OP to have a concern. Hopefully myself and other PP have managed to put her mind at rest.

[PenguinsandtheTantrumofDoom]

Twinkle - Believe me, I understand the frustration of feeling you may get medical care that assesses risk based on an incorrect understanding of your due date. I have been there.

But they will base your due date on measurements at your 12 week scan and things you can tell them (other than revealing it was IVF!) won't change their mind. It was physically impossible for me to be due as early as they said, but the date was the date.

I'd try and push it to the back of your mind and hope things adjust by 12 weeks. If not, hopefully this little one will wait until term to arrive and you won't need to worry.

[ostrichneck]

Rather frustrating in such a delicate board that's all happygojo - the statement I'm really not happy about dating behind sounds more ilke a tantrum to me.

I imagine that 100% of women who came out of a scan with no bad news would just be breathing a huge sigh of relief. Hopefully you other PP's will have put her mind to rest. About what I don't know, but hopefully so.

[PenguinsandtheTantrumofDoom]

It isn't a tantrum to worry that an incorrect due date will affect your medical care.

You can be relieved that there are no identified problems and still be concerned by that.

[happygojo]

Ostrich having had a scan that gave me bad news in my first pregnancy, being dated behind would also be a massive worry for me. Maybe for different reasons to OP, but a worry all the same. Also you can't tell OPs tone from a post, nor do you know her story.

Twinkle I bet you are bang on 12 weeks or even a bit ahead at your next scan. 8 week scans are rarely accurate because they are measuring something so teeny at that stage. I am sure you will be fine.