Haven't been trying to conceive but all I was told at the time was that you should wait a year. I don't think it is likely to prevent you from conceiving. Did your doctor tell you this was likely to be a side effect? 

I do know Sile Seoige (an Irish celebrity) has two children after thyroid cancer and I think she had radioiodine treatment.

Thank you for your reply [@MargaretMary]‍ 

I am meeting the oncologist next week. My consultant did say RAI does pose risks therefore to discuss this with oncology team.  Of course, naturally I've been reading a lot and majority of studies and information online leans towards potential infertility or likelihood of spontaneous abortion as the radioactivity destroys and damages the remaining egg supply . It's all so daunting.