Hello!
I've had some early scans due to pain, and 2 weeks ago I had pregnancy of unknown location, 6 days ago there was a small gestational sac and today a sac with a baby and HB inside 
The sonographer also measured another sac next door, but said it was a lot smaller and she'd guess it was not an ongoing twin pregnancy.
However, a week ago I had an empty sac and today a fetus with HB could be seen so I know it can be just a difference in days for development.
I'm extremely grateful for one baby, I'm just wanting to hear stories of similar things happening to you ladies so I can prepare myself at the 12/40 scan.
Thanks 