The menstrual cycle is controlled by a close association between the ovaries and the pituitary gland. These both secrete hormones at different levels during your cycle to control the cycle events. Any irregularity points to an imbalance in the communication between these hormones and these imbalances can be caused by changes in diet, stress, infections, metabolic conditions such as polycystic ovary syndrome and medications. The simplest way to restore this balance is through the use of a light oral contraceptive pill or progesterone cream, provided that it is safe to use in each individual case. The pill and cream will guide the hormones back into their correct phases and regulate your cycle. Any irregularity that is not corrected within 3 months must be investigated further by blood tests and an ultrasound.