Is it ok to do all of your Professional level papers before you've secured a training contract?

If you've done P1/ P2 / P3 but haven't secured a full time training contract. Should you wait until you have a training contract, before you do the last 2 exams? which will be Advanced Tax and Adv Audit for me...P5 and P6...

I'd like to apply to a big 4 company.

adv audit is actually P7, but anway yes its fine, if you require any private tuition for the P6 module i can help you as I teach this subject.