Trying to conceive for 16 months now

About three months ago I was told I have pcos and was put on metformin and every three months I go to see my obgyn so he can give me a pill to start my period I been trying to get pregnant for over 16 months and he will not give me clomid when his nurse even said it doesn't cause a high risk of having twins how can I be more firm on saying my goals to get pregnant and not to loose weight right now