There is a "sticky" here that talks about diagnosing Lupus and it discusses many of the lab tests that may be used in the diagnostic process. This might give you some idea of what to expect and why some tests are ordered.
Also, it is often a good idea to write down any questions that you may have and write down a list of your symptoms so that you can take them with you to your appointment with your rheumatologist.
Please keep us posted on how your appointment goes and what your doctor thinks. We will also be more than happy to help you and to answer any questions that you might have.
Best of Luck
Peace and Blessings
Look For The Good and Praise It!