You should report changes in employment to your DSO as soon as possible. SEVP recommends that you report any change within 10 business days of the change to avoid situations where a DHS official may determine the student is out of status. The following summarizes the best way you should report, if:
Change to a new job:
More than 10 days of unemployment
Decides to exit the United States and complete your F-1 status prior to the end date of OPT
STEM OPT Hub -from the Student and Exchange Visitor Program (SEVP) Study in the States
OPT Extension for STEM Students (STEM OPT) -from U.S. Citizenship and Immigration Services (USCIS) [Last Updated: 01/24/2018]