Confused about conception date and due date?

[Confusedmumma91]

Hi everyone. First time posting I just need some advice as I am very confused by something, I am also a FTM currently 20+3(?).

My LMP was the 19th of September, with my predicted ovulation date being the 7th of October. I have irregular periods due to endometriosis but they're usually between 30-33 days. My first positive pregnancy test, though very faint was on the 24th of October.

My 12 week scan was performed on 12+1 with my due date being the 25th of June. This was then determined to be false and my actual due date to be 21st of June with the baby measuring at 12+5.

This would mean that I ovulated/conceived on or around the 29th of September, 10 days after my last period, but my periods last for around 5 days.

I had my 20 week scan a few days ago and the sonographer said the baby is currently on the 53rd percentile but could they potentially have the due date wrong? Could the baby just be measuring a bit big for its actual gestation age?

I'm just very confused.

Due date isn’t based on your conception, it’s based on the size that baby measures at

As PP said, they base it on measurements but I wouldn't dwell on it. Due dates are an estimate and most babies arrive 2 weeks either side of their due date.

Also the baby's growth may change throughout your pregnancy but if you still have concerns, bring it up next time you see your midwife.

Best of luck

I am just concerned because I got really black out drunk and I'm unsure of if something happened to me by somebody I know who took me home, I'm just really worried and I think it's just compounding. I'm sorry I just feel like I'm going a bit mad

Pregnancy weeks are weird. They are supposed to start on the first day of your last period, even though that means you won't be pregnant until week 2 of your pregnancy 🤔

https://www.nhs.uk/pregnancy/week-by-week/1-to-12/1-2-3-weeks/

I wouldn't worry too much

With my first they put my due date based on a date two weeks after the last time I'd had sex so I knew it was wrong but they said they had to go off what I measured so her due date moved from March 12 to March 27 so it's very possible it's wrong based on the measurements

i knew exactly when I conceived due to fertility treatment but they dated me a week ahead based on my measurements on scan. I spoke to my consultant who said they have to go by the 12 week scan measure, but she would bear in mind I was certain I was a week behind this. Baby arrived at what they say was 34 weeks but constantly being considered as ‘especially sick’ and ‘needing a lot of support’ which pretty much confirmed that they weren’t a 34 weeker but a 33 weeker as I had been saying all along!

Oh I'm very sorry to hear this! I hope you're getting some support if you feel you need it