Need help

Ok ladies AF is due tomorrow and I have been having really bad lower back pains along with higher than normal bbt I was just wondering when I should test to see if I am actually pregnant or not. I know they say that you should wait to test when you are 10 or 15 dpo but the way that cycles are I only go to 5dpo that's because I am irregular. Should u test tomorrow if AF does not show or how long should I wait