TTC with metformin and hypothyroid

Melissa • 25 and pregnant with our first little Peanut!
I was recently put on metformin for insulin resistance. I take 1500mg's right now. I am working up to 2000. I also take 50mcg's of levithyroxine daily. 
​I've heard that the metformin will help but the thyroid issue could cause me to have trouble conceiving. Any insight?