Because she got a call in public and she had to take the call to make the appointment, if not, she waits another day/week/month whatever the case may be.

Some people don't bring cars to work for whatever reason. Plus this person may be in school or something like that. But also, what's wrong with having private conversations in public? As long as you aren't getting violent and scaring the people around you or embarrassing the person you're talking to. I guess it could be a problem if she had to describe the problem in detail while people were stuck near her listening to it. But just a passing mention and people are free to walk away if they don't want to hear it? Not a problem. I can understand why she was shy about it, but if she had just said it confidently it wouldn't be wrong.

i was searching for this comment! you shouldn't get down voted. personal issues require privacy - an empty room, bathroom...if you know the problem causes you embarassment, why not tried to prevent awkward situations?

You're* Screw that, I'll discuss personal things over the phone with my doctor whereever if it's the only time of day I can call him/her. 'What's wrong?' 'Yes, my rectum is making this silly noise I've not heard before. Not sure the issue.' You don't know the OP's situation, and to go and say it should wait for a private setting is inconsiderate to the way her schedule may work.

Yes, it's embarrassing. Especially considering we can hardly ever even mention a period without some people cringing into themselves. It may be natural and something that can't be helped but it doesn't stop other people from getting uncomfortable over stupid things.