Bereavement + exams?

So I have my A level exams starting next week, I experienced the death of a close relative 2 weeks ago and the death of a family friend last week.

Is it possible for me to apply for extenuating circumstances, I think that you can only apply for it after exams and that it has to be with the school's exam officer?

Could someone please provide me with some information regarding this? Do I need proof of struggling to cope with bereavement?