Unfortunately it is very normal... It is only after the surgery in your post op consult some 7 to 10 days later that they will have a good idea what the treatment should be.
I know how scary it feels but it is rather normal... If you are going in as a private patient you can ask to have a 2nd consult with the surgeon. It will cost you and probably give you no more info but it may give you a peace of mind.
Breast care nurses are absolutely fabulous and can help you understand more about your diagnosis and the process so it is worthwhile asking your surgeoun's office or the local hospital's Cancer Centre to put you in touch with her.
These ladies are absolutely invaluable and in daily contact with the whole breast cancer panel so really a good point of contact.
Hugs
Jel.