Hello Ebbie, I think from your post you are going to an outpatient appointment, is this correct?
If you are attending out patients, then it is similar to a medical outpatients except you don't have a physical examination, you just talk to the doctor.
You may have blood tests depending on what medication you are on or if you have any other underlying conditions.
I'm sure you will find the staff very understanding and kind, try not to worry too much, it won't be anywhere near as bad as you fear.