I don't think H&M runs that small, but compared to most stores now they do run smaller (since they don't vanity size). I'm a ridiculous 0/2 at places like Express, but a 6 at H&M. They still gap at the waist a bit but they fit really well everywhere else. It's weird, though, my hips are 37in and I'm a 6 at H&M, how are you an 8?