Early ultrasound experience- thought I was 6 weeks

[Wooshywombat]

Hi everyone, it's my first time posting here and I'm looking to ask about your experiences or any input you have on my situation :).

I went for a private transvaginal viability scan today for reassurance due to an early loss (CP) 4 months ago and because my husband and I are spending New years with my parents and will not be able to hide it from them (so wanted reassurance it isn't ectopic before telling them).
My last period started on 17/11/24 and my cycle is 26 days (fairly regular, 24-27 variance) which should have made me 6w0d today according to the clinic.

Little pea was measuring only 2.62mm so they have dated me at 5w2d. We saw a heartbeat (though not sure of exact heart rate), a yolk salk, foetal pole, gestational sac as per the photo. The nature of these private scans is tricky, I know, especially this early. The scan only took about 4 minutes and I know first trimester crown-rump length measurements can be off by +/- 5 days (https://radiopaedia.org/articles/crown-rump-length?lang=gb) at measuring gestational age so trying not to read into it.

Has anyone had a similar looking early viability ultrasound and gone on to successfully growing a bean and beyond? Worried about the size of the embryo Vs the size of the gestational sac.

Any words of reassurance welcome
Much love 🫶🏻 and thank you

It’s so early, also if your ovulation was 1-2 days later than usual you would be looking at 5+5-5+6 and on top of that like you said it can be normal for them to be up to 5 days out. Seeing a heartbeat is great news. The cycle I conceived my son I ovulated 6 days later than usual- I would have said it was a normal cycle length if I had not been tracking with ovulation tests.

In my last pregnancy I had a scan at 9+1 weeks for reassurance and I was certain of my dates with ovulation tests and they measured it -3 days behind. They explained the accuracy when it’s so tiny is hard.

Take the positives that it’s not ectopic and also there’s a heartbeat. Try not to focus on being x days behind, for all you know you could have ovulated a day or two later and there’s always estimation in the measurements when it’s that small.

I never had a scan earlier than 8 weeks though.

I had an early scan at EPU at 6 weeks due to previous losses and was dated 4 days behind what I thought. I was pretty certain about my dates because we’d been tracking everything. Same as you though, we saw a heartbeat and everything else was “where it should be” in the words of the consultant. My 8 week scan was also 4 days behind but by my 12 week scan things had caught up and my dates matched exactly what I had originally thought.

The consultant and sonographers all said it’s normal to be slightly out so early because everything is so tiny. Hope it all goes well for you!

Do you know when you ovulate? I always ovulate around day 20 so if my pregnancy had progressed I would have measured a week behind what I’d be if counting from my period.

Thank you for sharing your experiences@Blue2020 and @Electricfeels and for your reassurance. I echo what you both say about how difficult it is to measure and be precise this early on- especially with equipment and sonographer variability. The sonographer said the same, ie this is his best estimate, but it cannot be too accurate at this stage. Thanks for your well wishes

@Rycbar Good point! I have only tracked LH and was a 'quick peaker'. Always peaked on day 14, I imagine ovulating on day 15, but cannot know for sure as never tracked BBT.

At this stage it’s so hard to measure I wouldn’t worry. The fact you’ve seen a HB is good.

A few times I ovulated I actually got an LH surge two days before so you could be ovulating later than you realise! An LH surge isn’t always a guarantee either - it’s possible you surged and then didn’t ovulate and then ovulated slightly later in the cycle

I had an early scan (at around 9 weeks) and they dated me a few days behind when the dates given at my actual NHS scan a few weeks later.

It’s very early still, I wouldn’t worry.

Chances are it’ll be fine. If you read stories online the majority seem to catch up and be ok. I had similar but sadly mine didn’t work out. Was meant to be 6.4 (was tracking with strips and BBT) and measured 5.5 plus heartbeat. Was rescanned two weeks later and was measuring 6 weeks and no heartbeat.

I always ovulated day 11, so my pregnancies always had odd dates too.
Congratulations on the pregnancy. I know how scary this phase is after previous complications.

Wishing you a healthy and uneventful pregnancy.

Thanks for your insights and support everyone. Leaving a follow up here in case anyone comes across this thread later on. Had a follow up scan today (~3 weeks later) and baby has caught up and even measuring 1 day ahead at 9w5d. Spoke to the sonogpraher and she said I was most likely mismeasured last time because 2.6mm is very normal for 6w2d (not 5w2d) in her experience. This matches what I've read in medical texts (both my husband and I are in medicine, but obviously not obstetrics). Hope this provides reassurance to anyone facing uncertainty in early dates.

@Wooshywombat ah that’s great news, glad it’s all going well for you. I hope you have a smooth pregnancy.

Appreciate the update. Congratulations.

Hi! I am new here today. I had my LMP 21st December 2024 and got my BFP 18th January after period being 2/3 days late. My cycle is normally 24-26 days long.

I done a digital which was 2-3 weeks on 19th January and have booked an early scan for 8th Feb. I know there is mixed opinions on these but I feel like I just need to confirm everything is at least in the correct place but I’m wondering how I could be showing 2-3 weeks (on clear blue so 4/5/6 gestational). This would mean I conceived on my period and I’m not even sure I had sex then…

Could my last period have been fake? But also, it probably would have come up 3+ if that was the case.

Also, very little symptoms bar sore boobs and starting to feel the fatigue and general can’t be bothered doing anything feeling

That sounds normal. The tests (loosely) go by conception date not the same date used to calculate your due date, so 2-3 weeks on a clear blue on 19th Jan suggests a conception date around new year. Your LMP is the date they start counting your pregnancy from even though you aren’t in fact pregnant at that point.

For reference my LMP was 24th Dec. Ovulation was around 5th Jan, positive test 15th Jan (5 days before period due). I’m exactly 5 weeks today, meaning 5 weeks since my last period. I wasn’t pregnant on the day of my period of course, but that’s just how it’s calculated until you have your dating scan at 12 weeks.