Hi there,
Welcome to the board!!! Sorry to hear about your IF issues. It is so hard o understand all this stuff it is all so confusing. Just so you know my mother had irregular periods and underactive thyroid and had three kids w/o any tx at all. Given she is younger than you and I are now but today science has so many more abilities. I am glad AF finally came after medication and that you do have an appt with a specialist. They can get your thryroid problem under control. As for the your uterine lining I know that they have the ability to thicken or thin it out if need be. You may be put on progesterone they look like birth control pills but are not really b/c pills and they used to thin your lining. As for cysts, we have had cases on this board who have got pregnant with a cyst so it is possible

Sorry I don't know anything about metformin.
DH and I have been trying since we got married and we are both in our 30's so I understand how hard is it especially when newly married. Just be sure that you do not loose site of eachother during your IF journey it is hard enough to go through this, lean on eachother for support as much as possible. Please let us know how your appt goes on the 22nd. Wishing you all the best for a BFP in 2007!!!!
kathy