Mamai, I also have a higher tsh, 3.4 and ideally they would like it closer to 1 or 2. My clinic said that they will treat the higher tsh during my cycle with steroids and there is no need to start taking medication before as it's only slightly elevated. You are right, a gp will not prescribe you medication if it's below 5 and they are not very understanding or perhaps knowledgeable regarding thyroid issues and fertility anyways, at least from my experience. My advice would be to clarify with the clinic whether they will treat your elevated tsh during your cycle and if not get a private endocrinologist to look at your results and decide whether that should be treated before.
Regarding your t4 there should be a reference scale on your test results that will tell you whether yours is within range. Again, an endocrinologist might have a better understanding of how tsh, T4 and fertility interact. There are also some very knowledgeable ladies on this board who may be able to help