Going to the doctor for something embarrassing?

Okay, so if you're going to the doctor for something embarrassing do you have trouble telling the desk clerk what the appointment's for? How do you get around this? Example: I need to see a doctor about painful sex. This is unbelievably embarrassing. What's a discrete way to tell the desk clerk what the appointment is for? Also up to this point no doctor has had any helpful advice for me and it sucks to have to see a different one and give them the same story. I tend to blush allot when I discuss this topic. How can I bring up and talk about the topic as tactfully as possible?