Hi Rayburn! Thyroid issue can definitely cause problems conceiving, but if you're on medication for it, your levels are probably in the normal range and therefore shouldn't be an issue. How long have you been trying? They say it can take a normal, healthy couple up to a year to conceive. If you've been trying for longer than that, it's time to see a specialist.
As for IVF (in vitro fertilization), it is usually the last resort.