Fluid in Pelvic Area

I had CT Scan done a Tuesday to check for cancer and the results were negative. However, the radiologist did find fluid in my pelvic area. It is now Saturday and I received the letter in the mail today about the findings of my CT Scan. But I am wanting to find out what this could be. The radiologist said something about Endometriosis or an infection. Does anyone know what this is? I wont be able to see a doctor until Monday.

Thanks,
Mo'