I have PCOS and my thyroid has been removed, can I still get pregnant and if I do will the child be healthy?

I have PCOS and apparently that makes getting pregnant much more difficult. It also increases your risk for having complications. My thyroid was removed 3 years ago because of a weird nodule that may or may not have been cancerous, they're not sure. We adopted our son in 2008 but would love for him to have a sibling but I'm not sure if I can get pregnant, and if I do can I carry the baby to term? Also, will the child have any major complications? I don't think I could handle a miscarraige so would it be better for us not to even try and just adopt again? Please help. We've been married for 9 years and I haven't gotten pregnant yet (but I've only been off birth control pills for about 6 months). Also, has anyone had success using Soy Isoflavones to help with this?