我已经拿到receipt notice了，请问这样就等于有了18天延长了吗？ 您拿到OPT延期的receipt之后，就算是可以继续延长180天的有效工作身份。

If you file your STEM OPT extension application on time and your OPT period expires while your extension application is pending, we will automatically extend your employment authorization for 180 days. This automatic 180-day extension ceases once USCIS adjudicates your STEM OPT extension application.