Although I dislike disagreeing overtly with patients' own health care providers, your positive test for Ureaplasma is meaningless. It is a normal bacteria found in the genital tracts of at least 50% of sexually active people, and everybody has it at one time or another. It is one of the hundreds of bacterial that normally inhabit the genital tract. Some strains of Ureaplasma can cause nongonococcal urethritis (NGU) in men, but Ureplasma has never been found to be associated with signficant disease in women. In my STD clinic, we have never once tested a person for Ureaplasma in 30+ years, except when we're doing research on it.
In other words, you should not have been tested for it; and having ureaplasma is not a reason to take doxycycline or any other antibiotic. I'm sure it had nothing to do with your yeast infection.
Best wishes-- HHH, MD
And there is no reason for your partner to be tested or treated, if indeed he has no symptoms.