Infection problem

I went to the doctor last week, and she seemed to be very surprised after diagnosing me with infection. I've never had any sexual activities. and she reacted like I can only get this kind of infection from sex. So now I'm freaking out becouse I don't know where I've got this from.
I dont know what kind of infection I have. I only know my discharge have never been normal (since I was a child), and recently it was geting worse. (I had itchy yellow discharge.)
I took Fluconazol, and clotrimazole+betamethasone cream for five days. and now everything seems to be normal.
I'm going to see my doctor again soon but she doesn't really explain much, so I would really apriciate any explaination about my situation and the treatment I should expect..