Unless you have violated the law, or you are not in a bona fide marriage, your fears are unfounded. First of all, you will receive a 48 month extension letter when you submit an I-751. That will extend the expiration date of your card for 4 years. Secondly, a Green Card expiration date would affect only evidence of your legal status. It does not expire your status, itself, as a legal resident. The media is stirring up a lot of baseless fear mongering right now. I would just ignore it.