I have been on Methotrexate weekly injections since Sept 08 with no side effects. Take folic acid and get bloodwork done regularly.
If you have been on all the others don't know why this would be any scarier except they say you shouldn't be on it if you are wanting to get pregnant?
There is a thread titled 'methotrexate injections' on Page 10 right now started 12/27/09 you can check.