Seeing im wide awake worrying about my own probs (i just did a post here cos im really freaked), i thought i may as well reply to yours.

a yeast infection (thrush, most commonly) is caused by a build up of bacteria in the genital area. It most often causes itching and irritation (maybe a rash), and a thick sort of (sometimes coloured) discharge from the vagina.
However ive learnt that the symtoms of thrush can be very similar to Herpes, which is much more serious, so as much of overreaction/inconvienience it might be, you probably should get it checked out by a doc.

Thrush, luckily, is totally curably and easy to treat, so if you do have it, dont sweat it, cos you can get it cleared up in no time.

hope this helps...