Elevated AMH without PCOS? Metformin for unexplained infertility?

Has anyone here been put on metformin for unexplained infertility? I have mildly elevated AMH at 7, but no symptoms of PCOS and my specialist does not think I have it but hopes the metformin will regulate any hormone issues that may be occurring at ovulation that we haven't picked up on. I ovulate naturally every month, but they have me on femara in an attempt to stimulate more follies. We have been ttc more than 1.5 years, 4 rounds Clomid, one round Femara, 2 iuis, all unsuccessful. At our consult on Monday we were told we are just about out of options unless we want to start injectables cycles or IVF which my husband is just not comfortable with, so we're hopeful the metformin works and isn't just another failed attempt to get something to stick.