Someone please tell me what is going on?

It is not time for my period and for the past couple of weeks i have had cramps, horrible cramps like sometimes its hard to walk and awful abdominal and side and back pain. Last weekends i had some pink when wiping and called the doctor on call and he told me he thought i had something called diverticulitis and called me in an antibiotic and it hasn't helped at all... I'm getting really scared i feel run down and tired... I have a referral to an OBGYN and i really do not care about going to see him but I'm scared I could possibly have cancer or something it doesn't run in the family, like ovarian and cervical cancer but cancer does in fact run really heavy... I'm a 19 year old female and weigh about 185... someone please help me understand where this pain is coming from!! I have a history of having ovarian cyst also..