Re bras, consider that I’m a 32 - and if they did my cup size in a 30, I might actually get away with that. Ok, I look much bigger because I’m in a K cup, but even so, I don’t think for one second that I’m smaller than you round the rib cage. I’d pop into Bravissimo (there is one in the Eldon centre) and ask what they think. They ‘measure’ by eye and by looking at how your current bra fits.