Welcome newbies, lovely to have some more people here just starting out 
Lynsey so sorry you are still feeling so utterly shite. It's as much of a mental endurance test as a physical one isn't it. I find the constant nausea a huge pyschological challenge - and not in a gung ho, hurrah a challenge I can smash this! sort of way - in a waaah I am going to have a mental breakdown if this goes on much longer, sort of fashion. Just awful. From your other DC, when did it improve? Mine is receeding now, which is FABULOUS, except I don't actually feel any better, as I've started reducing my nausea meds so getting less help with it! Still, it gives me hope. Remember there are always more drugs - if you pop onto the hyperemesis thread they are a lovely and supportive bunch and you'll see lots of them are on 2 or 3 meds at the same time, so there are still options if you need more.
Truly children and scans are a headache. I presume you don't have anyone who could have him for a couple of hours - or would preschool be able to have him for an extra session? My hospital is strictly no children in scan room so I need childcare unless I want to go alone. Best laid plans can still foul up though - my 12 week scan in December I had arranged for DD to go to my friend's house except she was then ill and screamed All. Night. Long with an ear infection and then her eardrum perforated that morning necessitating emergency GP... so I had to leave DH at home to sort all that and went to the scan alone. Only to be told my baby had very serious abnormalities and we needed to see a consultant urgently. It depends on you how you feel you might manage in any one of many unpredictable situations. I was ok, delayed shock is very helpful at times, and I am sadly quite hardened to loss after DD1's death so I did actually shrug resignedly at the horror struck sonographer and say "well, I've had worse, thanks anyway" and left 
and drove home. It hit me later. I don't know, I'm waffling hugely, and will shut up now and hope you find a solution.
Was your tape ok tinkly? Sounds like you've had an utter nightmare year 
10+1, inching ever so slowly towards D Day and the first peek to see if there's anyone in there at all! I have a little pot belly now and my boobs are filling out a bit, starting to be curvy all over instead of my usual angular twig look. It makes me self concious and I want to hide because I don't want anyone to be guessing or asking me about it. I am avoiding my mother's phonecalls and wishing I hadn't had to tell her when I was so ill, because I feel a bit hunted and can't cope with the barage of enthusiasm and questions and total inability to take the hint that I don't want to talk about it. Certainly not telling her the scan date as I can feel the rage already at the "ooh just wishing you luck, can't wait to see a pic" phonecalls and the flashing answerphone when we get back showing she couldn't wait to hear from us.... I am such a cow, but I just can't deal with it, it makes me feel panicky and trapped.