Recommendations please..

My husband and I have been trying for our first baby for over 7 years with no luck.. I was given metformin along with my thyroid tablet

I had my first covid jab in may and in June found out we were finally pregnant.. does anyone know what I should be taking? Vitamin wise… Iv looked at the list in the Pfizer jab and it says potassium as one of the ingredients? Is this what I’m lacking?? Any help/advice would be much appreciated as we’ve tried basically everything

Edit..

Been taking metformin and folic acid since being referred to fertility back in 2018 and still waiting as they told me I was too fat and that I should starve myself to get on the list! And been taking vitamins before that too!