Status Expiration Date is usually on your I-94 card which was stamped when you entered the country. It indicates the maximum period that you may legally stay in the states, and it has nothing to do with your visa.
If you changed your status in the states, your new I-94 is on the approval notice.
Once you have submitted I-485, you are legal to stay here until a result of I-485, regardless your status expiration. Your such legal stay also has nothing to do with the fact you apply for AP or EAD.