What Causes Abdomen Pain With A Growing Ovary Cyst And Bleeding Mucus?

My daughter has been having extreme pain in her abdomen. She is 34 years old. She has had two ultrasounds showing that a cyst is located on her left ovary. One ultrasound was done in December and another in January showing that the cyst has grown. She has bleeding with mucous after her periods. Is this ovarian cancer or signs of it and does the cyst need to be removed?