The low TSH (hyperthyroidism) may be influencing conception rates -- if there is NO evidence of persistent/recurrent PTC (pap thy cancer) then it is reasonable to let the TSH drift up to around 0.2 -- again this depends on the status of the PTC. Of course, there may be other issues at work. The I-131, however, typically does not cause infertility
I see nobody has commented which they obviously don't know.
You should address your concerns with your gynocologist as TSH testing would probably be something they test with pregnant women.
I would think if your FT-3 and FT-4 are in a decent range the TSH should not have any effect on getting pregnant. I completely ignore TSH and only dose by FT's.