I know what you mean about Next......I tried the next in Chester, then I went to sealand Rd then to Broughton....none did maternity! Its a pain for me too as I have to by the petite jeans from next - the standard leg are still too long for me!
I've got a couple of pairs from Dorothy Perkins and also HM in Chester. If you go downstairs where the baby stuff is they do maternity stuff in there. You might have to have a root as some of the things are a little yucky but I've had some nice summer combats, a few t-shirts and a really nice hoodie (which I love) and they're really cheap!
Peacocks in Ellesmere port is really good for maternity too!
If your thinking of new look the one in Chester is rubbish for Maternity, I've had a few things and they've not been particualy nice (but I didn't have much choice) all my tops have came apart in the wash!
I've lived in track pants from sports soccer (So comfy & Cheap) & hoodie.......I feel like Chester's version of Vicky Pollard!