Hey Jen, my pleasure hon.
My GP is freaking clueless!! It was my endocrinologist who detected it (paid privately through my insurance as I was unhappy about having found thyroid antibodies in my blood results at St Mary's but nobody bothering to put me on anything for them after 3 mc's) and Shehata who insisted that it really needs to be below 2.5 if we are to ttc again. Once my repeat bloods came back (through the NHS) my GP phoned to say that my results were not alarming, borderline ok so no need to change anything (the TSH was still unmoved at 5.6), so when I pointed this out to her she said, well in this case I won't object to raise your thyroxine to 50mcg - which I was already on- and when I pointed THAT out to her, she goes, well ok then we can raise it to 75 or 100? Whatever you want (!!!?? wtf??!)
So now my thyroid management is also with Shehata with the odd intermediate test through my GP.
My friends all live in London, where the ARCG is based. It has top IVF success rates in the country but also deals with patients with autoimmune reproductive issues who need to manage them as part of naturally trying to conceive (without necessarily progressing with IVF).
They will do the Chicago NK tests (also done by the Lister clinic under Dr Thum who's another specialist with excellent reputation) and Dr Gorgy (also IVF specialist who deals with immunology issues). They are all based in London I'm afraid and they are all highly expensive (but then again, IVF is also a very costly process)
My friend from work had been ttc for at least 3 years before doing a round of IVF under the NHS which ended up in a chemical. Then had another 2 failed IVF attempts in Slovenia (where she's from as it's cheaper there) before taking a pause to see what to do next. They were about to give up when they read on Taranissi and his very "unconventional" but highly successful method of work and his high IVF success rates. So they started off getting checked by him for autoimmune issues, with the intention to do IVF with him once she was on an immuno-suppressant treatment plan. 2 months into steroid treatment from post ov, she magically conceived naturally for the first time in her life (and at 41 years old if I may add) and they had their little girl last Jan (they were due the same week as my 20 week mmc little boy was due sadly 
)
Shehata's approach is very similar in that he checks for NK's first, then puts you on a treatment plan depending on your results and re-assesses you every 2/3 months if you haven't conceived in that time. Another lady I know from a similar facebook support group under S's care who is now 44 is in a super ovulation treatment plan currently. So there are ways around ttc naturally before embarking into further IVF attempts- and you are still under 40 so it's not that you've got numbered days!
But it's best to discuss your personal medical history with an immunology specialist who is knowledgeable in hormonal/thyroid imbalances in case it is indeed IVF which would have the maximum chances of success in your specific case.
It's very diff hon, nobody seems to have the one magic answer but we're all ploughing through it.
Also forgot to mention that my thyroid issue was caused by Hashimoto's which is an auto immune thyroid attacking condition. I will never know if I had this the whole time and whether this was the reason for my losses it was un-diagnosed or the other way around (that the rmc's have caused havoc to my immune system and my thyroid as a result)
xx