No two boobs are going to be exactly the same, imho... your breasts will look cis female, after all, they are made the same, right? Breasts are just balls of fat, and hormones will start directing new fat to your upper region roughly 60 to 90 days on HRT. It will take years for them to develop into the boobs you want... and even then, you most likely still won't be happy. Most women aren't happy with their boobs, from my experience, anyways. I am not sure why your doctor told you that, my doctor told me I will most likely be about the size of my mother or slightly smaller or slightly bigger, which she is a C cup. I am already at a C cup 4 months in my transition, my back is what giving me most issues as it's not used to the upper weight :\