Hey Livvy,
I’m in for 4th Jan it’s coming around so fast! I’d definely get some ordered now if you can I’m usually a 32 so I bought a small (which is 32) I highly recommend the iBra it’s so comfy, I bought the ultimate too but had to exchange it for an x-small as the small in that was way too big as it comes down quite far on me so was loose at the bottom, I’ll only be wearing the ultimate when I’m further into healing. The iBra fits perfectly it’s not too tight and not too loose but I can loosen it at the front still if it gets too tight after surgery, I was confused too but honestly I’d just stick with your normal back size. Xx