I've got to change pill from microgynon to Cerazette due to migraines. I'm scared that changing to cerazette will make my breasts shrink? I started on microgynon when I was 15 and not sure if my breasts grew naturally or because of the pill. I'm only a b cup now but I'm just scared that I'm going to go back to having nothing when I change to cerazette? I really don't want them to shrink.