Extreme pain in lower right side, back, hip area, and abdomen. What is the cause of this?

I noticed this about a week ago. And it has progressively became much worse. I'm 19 and female. The type of pain is hard to describe. It is very uncomfortable and almost debilitating. I have also been experiencing random moments of nausea. I went to the doctor and had 2 x rays, and an ultra sound done, and my doctor said the results were fairly normal. Sometimes the pain will only be in my lower back and no where else, and then it will be in my lower hip or just my entire right side. It seems to be getting much worse and it concerns me that even my doctor doesn't seem to have an answer for me. Please help.