I am really struggling too. Not helped by being a size 18 and a lot of ranges stop at a 16. I have bought some things on Vinted inc two pairs of maternity jeans which are not comfortable at all! I've ordered and returned a few other maternity bits. Jeans are my main problem. I'm 12 weeks so don't have much of a bump yet but all my jeans and leggings are too tight.
I'm wearing a lot of my oversized shirts and they are all still fine, but it's getting a lot colder in Scotland so I'm in need of cosy things!
So far I've had success with
Next - various brands but I've bought a nice sage green fleece jumper from Mountain Warehouse. Also bought a two pack of maternity leggings from Next.
New Look - returned all the dresses as quite frankly they were thin and cheap, but love a long line pale grey jumper and I'm going to order in olive green too.
Vinted - a Seasalt maternity dress (looks like they no longer make new maternity clothes). A Mothercare denim pinafore dress - bit tight but hoping it might look better once I have a rounded bump.
M&S - bought a bigger pair of standard jeggings but they are so baggy on my legs that I don't really like how they look. Alos bought a couple of long sleeved tops from Autograph that I like, just in a bigger size.
A lot of people have recommended H&M, ASOS, River Island but I wouldn't shop there anyway so it doesn't really feel like my style or quality. I'm going to try George at Asda for some jeggings hopefully.
I've returned
A lovely striped tunic from Seraphine that was too tight and an 18 is the biggest they do.
A denim tunic top and a striped top from Frugi. Bit frumpy.
Maternity jeggings from M&S - just didn't fit right.