How much time after you finished chemo for breast cancer till your periods are regular?

Maybe forever!: At your age of 46, it's very likely that chemotherapy will put you into menopause. However, if you are still having periods, it can take a year or more for them to become regular, and sometimes they never get back to normal. You are likely approaching menopause, and during this time it's common to have irregular periods, which can make for some unpleasant surprises! You're not alone...