I rang the imaging centre today, it is a womens only centre. The lady on the phone was very helpful, pleasant and knowledgeable.

The final decision is- scan must be between 11 weeks 4 days and 13 weeks 4 days. They prefer it to be 12 weeks 4 days as that is the middle time and therefore the best.

Bloods must be taken at 10 weeks which can then be matched with the scan. Results are available on the same day or can be received over the phone.

Thanks everyone for your help and much needed advice,
I'm booked in for a scan 12 weeks and 4 day.
cheers,