General question

Once AF leaves hubby and I will try one last time this time we are going to try using pre seed along with ovulation strips to track ovulation for the very first time . I have never tried to track ovulation before . So question is when should I start using the strips ? A little background my cycles are VERY IRREGULAR. I’ve gone from 60 to 38 to 45 to 26 it is different every time. Most common length is 7 days but some months I only have it for 3 - 5 days. Any and all advice or any tips that you ladies have tried are greatly appreciated. Thank you in advance