Patient virgin has big clitoris. Ob/gyne said:surgery to be done clitoral excision. Can surgery be done 3 days before menstrual period.

Get 2nd opinion. I am not an ob/gyn, but I have not heard of a clitoral excision. It sounds like it could do more harm than good. Wait to have surgery until either you get another opinion or hopefully one of the ob/gyns here will weigh in on this procedure.