Hi Daisy I am 17 weeks and still looking into pg clothes and bra options.
I used to wear underwired bras but read that they might restrict the blood flow to the growing breast.
www.babycentre.co.uk/pregnancy/isitsafeto/underwirebraexpert/
so as a temporary measure I've moved to crop tops which for now are accommodating any growth, like this one
www.sweatybetty.com/Scripts/prodView.asp?idproduct=491&idcategory=&title=Moonlight_Crop_Top(sB)#
I've had the most luck with blooming marvelous fitting me, but like everything a different store will suit a different body shape.
In the beginning I wore the bump bands which were useful. Then as I got a bump I found my trousers fell down and they weren't as comfortable.
I found the same as paranoidft in that the trousers that pull over the bump are the most comfortable for me. Although you need to make sure they won't fall down if your bump isn't big enough yet. I tried on some of the elasticated trousers with the buttons on but they weren't comfortable for me and I worried I was most likely to bust the buttons if I wore them lots.
The only other recommendation I have is to check that your local high st shop eg. Next, Hennes etc. has the maternity range by ringing them first as some don't and the flagship stores have the best selection.
I would try different options in the stores if can before ordering online so you can get a better idea of styles that suit. I am trying to get stuff that will expand the most so I don't have to keep buying new stuff.
I hope you this helps. Good luck