Well, boils in general are caused mostly by Staphylococcus aureus. They are easily spread and it is easy to reinfect yourself. A lot of them are resistant, such as the MRSA strains. Have they don't a culture on the boil that way they can test to see if it responds to the antibiotics. Does it come and go when you take the antibiotics or stay there all the time? Sometimes they will drain them as well.
consult your gynocologist as soon as possible.
Did your doc rule out herpes? Im assuming yes but if they haven't married or not request the test. I would and im married too.