Thank you all so much for your lovely messages!! Being the hugely over-emotional wreck that I currently am, I blubbed whilst reading them!!
DH and I have spent the evening trying to carry on as normal but with regular intervals of saying "Twins. TWINS!! TWO babies!!". We've also been looking at double buggies, the costs of buying two cots / moses baskets / everything else and have slightly freaked out. Still overwhelmed but just SO happy.
nickstermum - they are identical apparently!! We have another scan booked on 31st Jan to confirm this and to confirm whether they are sharing the same yolk sac as she couldn't quite tell today.
Littlebeaut - no we weren't expecting it AT. ALL. I was full on expecting to be told I'd had a MMC and had even wrapped up stuff at work in anticipation of being on sick leave from this afternoon. To go from being convinced I'm having no baby to finding out I'm having TWO was possibly the most amazing experience of my life.
neverlookback & CappuccinoCarrie - scared and terrified are definitely two of the emotions vieing for top position in my mind at the moment, but pure joy is staying in prime position for now. Although having just made DH watch last night's OBEM, terrified is creeping up. I have to do that TWICE. Eeek.
Just wondered if anyone else has started / plans to start a pregnancy journal? I would love to (although no idea where I'll find the time) and wondered if anyone can recommend one? Have looked on amazon and there are loads and not sure which is best 
Told all my family the news today! Much blubbing and excitment on the phone - esp my sister who just roared for a full minute! It was almost as wonderful as seeing the heartbeats!