ok so i figured out they were 31 days over aug and sept and af has just finished and this time it was only 25 days So how do u figure out ur cycle length when they are that irregular

Witch is playing tricks me thinks ive always been 28/9 days

any help ?

You need to know when you ovulate and what your luteal phase is because it always stays the same, when periods are irregular its leading up to ovulation that changes x