Gosh, lots of good suggestions here - thanks ladies! Have looked at Formes but they don't seem to go down that small and are quite pricey.
Am thinking of splashing out on a pair of 'designer' maternity jeans - found a shop called Push in Islington and emailed them, and some of the makes they stock (Seraphine and Juicy I think) go down small enough but only come in a standard 32" leg, so would have to be shortened. I don't know why, but jeans are the one item of clothing I hate to shorten as you lose the 'jeans hem' (even if you get the stitching done the same) and they look shortened, if that makes sense. But beggars can't be choosers I guess.
NotaSheep, I have tried on a few things just in a bigger size, but the problem with that is that although they fit round my bump (at the moment) they hang off my hips and bum as I'm no bigger anywhere else. There's also the not knowing how long something just a size or two bigger will last - if it's only a matter of weeks it's a bit of a false economy.
My mum is going to New York in two weeks' time so we're going to trawl the Gap website so she has some ideas on what to get me. Of course, there's a risk that stuff won't fit but I work with a couple of American academics who will no doubt be heading to the US at Christmas so I could maybe beg them to take stuff back that doesn't fit if need be (must tell my mum not to use her credit card). Didn't know you could order Gap stuff through Amazon - will look into that.
Indith, I found that with TopShop. I tried on some size 6 trousers (about the only pair they did actually have in a 6) and they really gaped at the back as well as being way too long. I've found the same trousers on their website in a 30" length so will order those - if they're a bit big round the waist I can always wear a belt for the time being. That's a great idea about looking in Tall sections for longer-length jumpers and tops - will try that, thanks.
I'm not a skirt/dress person at all, and I don't see why I should have to abandon trousers just because I'm pregnant. It'll only make me feel even more self-conscious if I'm forced to completely change my style and wear clothes I wouldn't normally choose, so I'd prefer to avoid that route if I can. I might go for an A-line knee-length skirt with long boots and a sweater, but that's as 'girly' as I get unless I'm going to a wedding or something.
Taffy, poor you - you must have even more problem than me at 4'10". Normalness, how nice to be able to have things made - sadly I don't know anyone who's handy with a sewing machine and can't really afford to have things made for me.
Mercy, thanks for the Reet Petite link - will check that out too.