That's tricky. You are absolutely right that flax is supposed to be good for women's health. And usually aids in a more regulated period along with fewer hormonal symptoms. I was thinking about taking it for menopausal symptoms! However, as it does have some effect (and this really isn't that well studied like all supplements), it could also impact your cycle to be irregular. Being irregular can happen whenever our hormones shift. This may be what is going on. And I'd think it would get more 'normal' as your body became used to the new intake of flax. Other things that makes us late are stress, illness, weight gain or loss, changes in routine, etc. There's always the test it and see method of finding out which is to discontinue the flax. And make sure you talk to your doctor, do your annual check up and all that good stuff.