D. - yes, you must find a GOOD endocrinologist. Here's what happened to me. I was trying to get pg and my TSH was supposedly in the "normal range" which was under 5 (this is hugely debated by the endocrinologists associations - there has been a debate that that level for what is considered normal should be under 3). I tried getting pg and miscarried twice. My reproductive endocrinologist (with Fertility Centers of Illinois - who I do NOT recommend) never said a word to me about my TSH level which at the time was on the very high end of normal. I went for my annual physical and my TSH came up at 5.7 - now above normal. My general physician, who BTW, was also trying to get pg with the same doc at FCI, said I absolutely should not try to conceive until my TSH was under 3 and she put me on synthroid.
MY RE at FCI STILL wanted me to proceed with the next cycle, but I said no way and I started to question her about why they didn't say anything to me about my FSH level - and she said, well, it was within the normal range. However, when I pressed her she admitted that the ideal TSH for trying to conceive is under 3. Now I was spending thousands on fertility treatments and she never raised this during my first two attempts - that I was outside the ideal range for ttcing. She also NEVER told me that for many women who have thyroid issues, they also have thyroid antibodies which are connected to higher rates of miscarriage. She actually had the nerve to say to me when I asked her after my second miscarriage if there were any immune issues I should be tested for - that it didn't matter because there were no proven solutions for immune issues. Hello! It mattered to me - that is MY decision to make (whether if I had immune issues if I wanted to try treatments).
Due to insurance issues, I ended up changing fertility clinics anyway - to Dr. Randy Morris in Naperville - who I HIGHLY recommend and he tested me for antithyroid antibodies and sure enough, they were present and very high. There is no "cure" for this although for some women if they're TSH lowers, so do their antibodies. He also put me on Selenium, which has been shown to help for some women. However, even though my TSH was at 2.5, and I was on Selenium, I miscarried again on my next try. Dr. Morris said if I kept trying he thought I might get pg and stay pg, but at 45, using donor eggs is expensive (mine were no good)and I'd been ttcing for 2.5 years, I just decided I was done and have now moved on to adoption.
So, you should a) find a good, proactive endocrinologist and b) you should be tested for antithyroid antibodies and c) not ttc until you get this under control - something is not right/normal. Every woman's "normal" level is different. I feel great at 2.5, although I am still struggling with weight gain. Trust your instinct and find a doctor who wants to help you.