Ultrasound query

[Swlondon123]

Hi everyone,

Can someone please let me know how accurate ultrasound scans are?

I had a one night fling with a guy on the 15th Aug before I met my current boyfriend.

I am now pregnant with my current boyfriends baby. My last period was on 20th Sep. I am around 15 weeks pregnant.

Is it possible for the ultrasound to be off by 1 month or to be pregnant and not to know about it? How accurate can the dates be?

I have been for a 3 scans (last one at 12 weeks and they said I am 12 weeks and 5 days pregnant). But I am still paranoid about how correct ultrasounds can be. Is it possible to be pregnant 17 weeks but for the ultrasound to show that I am 12 weeks pregnant?

Can anyone please help?

Ime scans can be a few days off not a few weeks.

Your 12 week scan is the dating scan. That's the date they go with so it should be fairly accurate. I think it's highly unlikely it could be 5 weeks out at that stage. Try not to worry.

I don't think they can be that inaccurate it's fairly certain to be your boyfriends

If your scan coincides with the date of your last period then I think it's correct.

Thank you ladies. I have asked the midwife and a few doctors (!) and they said its not possible to be 17 weeks pregnant and for scan to show 12 weeks. But I am an anxious type who gets very worried which is why I posted on here.

As the others said maybe a few days but highly unlikely to be 5 weeks wrong as its based on the growth of the baby

I think we're all the anxious type when we're pregnant! Every day I find something new to worry about - I blame the hormones!