Help me refine an idea for a one act play?

Hello. At school I am forced to write a one act play. My idea is ok, but needs to be worked on. I wanted a simple scene, so chose a doctors office. The basic plot is that there is a girl in the waiting room of the doctors, and everything is going horribly. There is a man who keeps breathing down her neck, and leans over and starts blowing on her hands. I want a couple of other situations to happen as well, like all the other patients being called in before her, or a man sneezing on her or something. The ending was going to be that she gets a mammogram and finds out the doctor doesnt have a license, but thats not going to work out, so I would also need a new idea. Any help?