How long to Breast cancer post surgery pathology results take?

Hi all

I'm in tomorrow for my lumpectomy and partial reconstruction but I've been warned that the post surgery pathology results will take 4-5 weeks or more! This seems like such a long time. Other results I've had have been quicker than they said  (MRI/genetic testing etc) so I'm hoping this will be the case here too. Surely they must be quicker tha  that if I'm supposed to have radiotherapy 4-5 weeks after surgery. 

I'm just wondering what other people's experiences are please. X