Thyroid Levels and TTC

Amanda • 33yo. TTC #1 for 18 months now. Starting IUI journey.
I'm 33 and have been actively trying to conceive for a year now. Past miscarriage over 5 years ago. Had thyroid levels tested and found they were at 0.018. I'm not sure if I should be concerned, demand medication, or continue to wait. Anyone been in a similar position?