Confused by dates , thought I was 7 weeks but told now only 6+1

[Km12345]

My last period was 27th August, I tested on 30th September with a strong positive

I went for an early private scan on Saturday due to bleeding, the estimated6+1

I then went for an NHS scan this morning and they measured again at 6+1 . Really confused
All was well with scans and I seen a little heart beat

Has this happened to anyone before? Do you think it will change again by 12 week scan ?

I had an early scan with the NHS when I was 7 weeks past LMP, but they dated me 6+1, I then had a private scan 2 weeks later and I was 3 days ahead of that first date. But I did ask at the first scan if it was okay and they said at the start it's all really small and tricky to get dead on, so I wouldn't worry at all if they haven't said anything.

Congratulations🥰

Firstly congratulations on your pregnancy :)

I'm 32 weeks now and still to this day can't figure how as all my LMP and intimate with my husband dates just don't add up. When we went for our 12 week scan the baby was in fact only just 10 weeks in size but strong healthy heart beat etc so no concerns and she's stayed 2 weeks behind all the way through.

I'd tested with a pregancy test when I was two weeks late for last period.. im usually quite regular but for some reason hadn't been that month. It completely threw me :)

I had an early NHS scan which put me a week behind what I thought. When I went for the 12 week scan I was 13 weeks so had caught up to original dates. That said lots of people don't catch up and all is well, things like late ovulation, late implantation etc can easily cause a week to be lost.

With my first I had the same experience as @Taenia except she began measuring big but policy is to not change the due date from that stated at the dating scan.

Your LMP doesn't tell you when you conceived. If I start my period on the same day as a friend and we both conceive on that cycle, it doesn't follow that we will have the same due date. I ovulate on day 11/12 and a friend may very well have long cycles and ovulate on day 21. That's already a 10 day discrepancy. Throw in the fact that implantation time can vary, early scans are only accurate to 5 days in each direction due to myriad factors and actually, you expect some level of discrepancy.

Even if you know when you had sex, sperm can live for 5 days or more so the day of sex might not be the day you conceive.

If it all looks as it should then that's all you can know for now.

Congratulations. I hope you have a healthy pregnancy.

My pregnancy was dated back four days at an early EPU scan, and 6 more at 12 weeks.., baby is now 31 weeks measuring 33, but everyone seems happy enough. Dates are a guessing game anyway, the science behind due dates is lax.

Congratulations on your pregnancy!

thank you all for your positive comments :)