Aimee I had 400 implants under the muscle last year and was smaller than you to start with and was a 34d cup so you will prob end up bigger. I would get a back size up (unless it’s a macom) for just after surgery to allow for swelling, swelling ribs were quite swollen and my sports bra was far too tight lol!! The m&s zip front sports bra is comfy and really stretchy, I didn’t get on with the macom but it’s all down to personal preference. X