Case 1. I think that the most probable diagnosis is endometriosis because of monthly pain plus pelvic mass. The differential diagnosis could be an ectopic pregnancy or pelvic tumor of connective tissue as some kind of sarcoma. This patient has to go to surgical exploration.
Case 2 must be studied as unknown origin fever with diagnosis probable of brucellosis, Lyme disease, rickettsiosis, and malaria, depending on the demographic area.
Neither of both cases is my expertise area but are very interesting and I'd like to know expert opinion