Hi, thanks for your question. Expired birth control pills can keep working but they may not work as well. When the birth control pills are expired, manufacturers can no longer guarantee that the drug isn’t deteriorating and that the pills will be effective contraception. Because of this, taking expired birth control pills may result in an unwanted pregnancy. You can use the expired pills until you can get a new prescription but in the meantime a back up method of birthcontrol like condoms is recommended. If you do have unprotected sex while using expired birth control pills, then it would be recommended to use Plan B the emergency contraceptive pill to prevent a pregnancy.
Let us know if this does not answer your question or if you have any more questions or concerns.