What I do know is that as enjoyable as oral sex could be it's still a risky business because parasites like thread worms, which CDC estimate 40 million people in the US are carrying hangs out around said areas. Some people have the Pin/Thread worm infection and don't have any symptoms, but one of the most common symptom is a foul discharge. Thread worms are highly contagious and can be at times very hard to be rid of. So if you are for real, you better think twice about not talking to your Mom.
Regarding your immediate problem, call the doctor's office that prescribed the pills and find out of they can be taken vaginally. If not, ask about another kind of medication to get rid of the infection. Did they just phone it in, or were you examined? If you weren't examined, I would make an appointment to be checked, to be certain it's a yeast infection.
Oral sex does not inevitably lead to a yeast infection.