These dates don't make sense!!!

[Junobug]

I found out I was unexpectedly pregnant 4 weeks ago. My LMP was 1st May but I'm irregular so that doesn't really tell you anything. I definitely didn't feel the 11weeks that would have made me so the midwife sent me for a dating scan. The sonographer said I looked about 6 weeks pregnant, the measurement showed just 7w. There was a heartbeat.
But this means I would have tested positive at, if not before 3 weeks! And I'm sure we did not dtd the week it would make conception.

So can the scan really be up to 2 weeks out? Or is it possible that even though there's a heartbeat, it's not progressing properly? I'm a bit all over the place at the moment. I was hoping a dating scan would reassure me but it's confused me more.

I think 1 week out is normal? I think mine has put me 6 days ahead contrary to my ovulation/conception dates.

You may have got a positive at just under 4 weeks. Did you have sex 6ish weeks ago? That would make you 8 weeks and the scan is just a week out.

I don't know a lot about mmc but if there's a heartbeat that's a good sign

I got my positive at 3w+3 so it’s possible to get a positive before 4 weeks.

Heartbeat is a really positive sign :) and dating scans before 12 weeks are known to not be as accurate so you might even out to dates that make sense at your next scan xx