Hi it would prob depend on what your boobs were like when you were nearer to the weight you are aiming for now. I've lost bout 3.5 stone with 4.5 still to go and I'm in smaller bras cos lost a lot off my back, but my cup size isn't any smaller yet, but from a distant memory of my slim days I was never particularly small up top.
I'm with the it will be in proportion camp so I wouldn't worry I'm sure other half won't be complaining x