What Causes Pelvic Pain?

my daughter complains about a pelvic pain-which she describes as an burning sensationon both sides of her lower abdomen,where the ovaries are located.Her ultrasoud didn`t show any problems and she was prescribed contraceptives to regulate her period ( she is not sexually active ) After 2 months on the pill the pain ( burning ) didn`t go away,.She also noticed some spotting between the periods. She`s 15 years old.