Steph -
That's weird they didn't explain about the thick lining..where I am, they explain everything (before, during, and after). I'm not too sure exactly what a thick lining does, but read it is caused by too much estrogen? (maybe?) and you are usually given provera to induce AF, which thins the lining. However, I read somewhere else that progesterone causes a thickening of the lining to prepare for pregnancy. Other than that, I really don't know. So sorry I can't help anymore than that. Keep us updated