tessiegirl here's where I've got all my stuff from. A mix of from both last pregnancy & this time around:
eBay - dresses & seraphine jeans
Topshop - dress
H&M - jeans, tights, winter jacket, non-mat strappy vests, basic tops
New look - work trousers, skinny jeans, tops
Seraphine - skinny jeans, leggings (which are FAB and like a second skin!)
Aldi (yes, Aldi!) - leggings, top
Primark - swimsuit (in size up), nightwear for hospital (in size up)
Jo Jo Maman Bebe - wrap tops and top (and planning on getting my post-birth big pants here too)
Asos - dress
Yumi - jumper (roomy baggy style so just my usual size)
Fat face - top & smock shirt (their stuff is roomily cut so get away with my usual size)
M&S - pjs in a size up
Mothercare - popper-front nighties
Plus I can still wear all my cardis because I never button them anyway.