Hi there...I can understand your concern. What medications has she been put on?? And what is the age of the patient? Irregular menstrual cycles can be due to several reasons like pcod, hormonal imbalance, drug intake, stress, anaemia, thyroid disorders, fibromas, endometriosis, etc. She will need detailed clinical examination and further investigations including ultrasound abdomen and pelvis. So kindly consult a gynaecologist for further evaluation.