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Dates don't match up. Confused.

(10 Posts)
FredKiller Fri 05-Apr-13 11:52:17

Have just had my 12 week scan and was told I'm 14 weeks (and therefore too late for a nuchal).

The thing is, I can't have got pregnant earlier in my cycle as we only DTD once that cycle. So how can I be 14 weeks?

Sonographer said I must have been pregnant before my last period. I knew I had ovulated late then, as I was stressing about bfing DS and luteal phases. But I thought it was impossible to get pg with a very short luteal phase?

Is it worth getting another scan, do you think? Sonographer seemed pretty certain but I just don't understand the biology of it. My last period was all totally normal too.


mistlethrush Fri 05-Apr-13 11:54:42

I was measuring at least 5 days over by 12 weeks - DS was (and still is) always large for his age. I was able to be very precise... we were going to start IVF that month!

Rockchick1984 Fri 05-Apr-13 11:57:23

It's difficult to get pregnant with a short LP - not impossible. Presumably what you thought was your last period must actually have been implantation bleeding? If you're worried then speak to your midwife about getting another scan.

FredKiller Fri 05-Apr-13 11:57:29

Thanks. I asked if it could just be a giant baby (like its brother) but she said no, developmentally it is definitely older.

I'm just worried because I'm going to miss the chance for a nuchal.

Also, it meant I was pg over NYE. When a lot of booze was taken.

MrsBungle Fri 05-Apr-13 11:59:26

I measured over a week ahead of where I should have been. I also only DTD once that month and it was on cycle day 20. My cycles are never over 28 days. I thought it would be impossible for me to be pregnant that month but I did. I also, as I said, measured ahead confused

With my first DC I measured a week behind. Again, I knew when I had DTD.

I don't understand any of it <v helpful, me!>

I suppose since it makes the difference of a nuchal test or not you might feel better to confirm with another scan?

FredKiller Fri 05-Apr-13 12:02:36

Maybe RockChick. It was a full on normal period though, so seems like a bit much for an implantation bleed.

eltsihT Fri 05-Apr-13 20:11:52

In all my pregnancies, I have been convinced my dates were wrong. By about 1 week. Was also very overdue with ds1 (15days), they work out dates by averages, so there is a little margin for error.

My 12 week scan turned out to be a 14 week scan supposedly this pregnancy. Interestingly at my 20 week scan (I was paying attention to the dates that were shown on the screen when they took measurements) dates varied between 18wks and 22 weeks.

I questioned my midwife about it and she said they wouldn't change the dates so I left it... I am just expecting to be overdue again this time round.

Flisspaps Fri 05-Apr-13 20:21:08

I had my 12 week scan when I was 15+4 (didn't want nuchal scan so not fussed by lateness).

They said I was 17w. I continued to work to my original date and not their revised date.

DS was born at 40+11 by their dates. 40+1 by mine (and laboured at 40w by my reckoning)

For all their measurements, calculations and estimates, I knew how pregnant I was.

I'd ask for another scan. You might not get it, but you can ask. What about the triple test (sorry if you've mentioned that)?

racheld33 Fri 05-Apr-13 20:33:59

I was charting my waking temps this time I got pregnant, so i know exactly what date I ovulated (and I know for certain I wasn't pregnant before then). I went for my dating scan when I was 11 + 6 according to my dates, and they said I was at least 8 days later on. After the scan, I spoke to the midwife and showed her my ovulation chart from the month I conceived. She agreed with me, and said if/when I go overdue and they want to induce me at 7-10 days over, tell them you want to wait another 7 days!

FredKiller Fri 05-Apr-13 20:53:26

Well, I spoke to a midwife who laughed at me and said that they would work to the sonographer's date and that obviously my cycles must have been irregular and I just didn't know when I'd conceived.

My cycles aren't irregular, but I admit that I wasn't sure when I was ovulating as I am still bfing. The month the sonographer said I'd conceived, I had done a clear blue ovulation kit, which had me down as ovulating on day 19 of my 27 week cycle. We DTD anyway but was unsurprised when I came on as usual, as an 8 day LP is very short.

It's kind of irrelevant really, as DH pointed out, the results of the nuchal probably wouldn't change anything for us either way. I think I was just a bit in shock and still don't understand the biology/period maths here.

I'm having the Barts quad test in a couple of weeks, but no one can really tell me how accurate it is vs. the nuchal. As I said, it's probably irrelevant but I'd like to be prepared, I guess.

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