So I had an early scan today to check it was in the right place, I'd had some sharp pain on the right side. Too early to see anything but there was a little sac and apparently evidence of the yolk all in the right place. I'm booked back for 3 weeks to check viability. Was slightly thrown by the second sac that appeared to be there! No history of twins. Consultant said far too early to say if it is twins, it may not develop as the sac is slightly smaller than the other one and no yolk could be seen. Was planning on 3 children, 4 would be a bit of a shock !