My Daughter Has Been Hurting On The Right Lower Abdomen

My daughter has been hurting on the right lower abdomen around the hip area in the front for over a year now. When it hurts she haves to lean over. There is also spotting. We have been to the doctor several times and hospitals. They all have taken ultrasounds and said nothing was wrong with her. I have been told to request they turn her on her side when taking a ultrasound. What could this be?