Sorry, I just noticed that I forgot the link to the checklist.
http://thyroid.about.com/cs/basics_starthere/a/hypochecklist.htm
First and foremost, TSH is a pituitary hormone that is affected by so many variables that it is totally inadequate as a diagnostic for Thyroid problems. At best it is an indicator to be considered along with much more important indicators such as symptoms, and also levels of the biologically active thyroid hormones, free T3 and free T4 (not the same as total T3 and total T4). Free T3 is the most important test because it largely regulates metabolism and many other body functions. Studies have shown that FT3 correlates best with hypothyroid symptoms, while FT4 and TSH did not correlate very well at all.
A good thyroid doctor is one that will treat you clinically by testing and adjusting FT3 and FT4 levels as necessary to relieve symptoms. Symptom relief should be all important, not test results. The best use of test results is to verify that the meds are increasing your hormone levels and to document the levels that make you feel your best.
So the first thing I recommend is to use the checklist in this link and mark off the symptoms you have. Make sure to take a copy of this to the appointment and give it to the doctor and discuss it. Then you should request further testing. Specifically you should request tests for free T3 and free T4, along with TSH. If they resist, then you should insist on FT3 and FT4 tests. Also ask about testing for the thyroid antibodies TPO ab and TG ab, to determine if the cause is Hashimoto's Thyroiditis.
Many members who are hypo also report that they needed testing for Vitamin D, B12, and iron/ferritin. So ask about those also.
When test results are available, then get a copy and post test results and reference ranges and members will be glad to help interpret and advise further.