Meant to be 8 weeks but measuring less!

[dollface22]

I'm a chronic anxiety sufferer, so I had a private scan today & sonographer did a internal scan and said I'm measuring 6.5-7 weeks! Then I checked on my scan photo it says 6w3 days based Upon the measurements of baby.

On my app it say from my previous period dates I should be 8 weeks today. I did have irregular period cycle for 6 months prior so some were 28 day cycles some were 38,37 & 29 day cycles. Is it calculated based on the LAST day of your last period or the FIRST Day?
My periods were also very short too.
Good news is she found a good heartbeat today ❤️ I'm just still a bit worried as to why I would be measuring Behind!
Has anyone had anything like this ? Thanks

It's based on the first day of your last period.

If you know when you ovulated then that might help clarify things?

First day of last period and at this gestation, the tiniest mismeasure can put the age way out. Give it a couple of weeks and get rescanned if that will help your anxiety

It's based on the first day of your last period, but that's on a regular 28 day cycle. If it was one of those months where you were having a 38 day cycle, then you'd be measuring 10 days behind!

I have irregular cycles, and was measuring 5 days behind, now 4 days behind.

It can even happen in women with clockwork-regular cycles (late implantation or something).

Please don't worry too much for the moment.

Thankyou! So my first day of my last period was 15/04 and it was 3 days long! I then ovulated on the 27/04 and had a positive pregnancy test 14/05.
Tryin not worry but I'm just grateful I've got a scan with a heartbeat 💓

How’d this end up ? 😬