My H1-B case has been pending with USCIS since 120 days. My OPT expires on Aug 19. However I will be on CAP-GAP after that. I am considering applying for an F1-STEM OPT Extension (I am a Civil Engineer working for a Civil Engg firm). Will approval of my OPT Extension cause any problem with approval of my H1-B or vice versa? If I get to know about H1-B approval when my OPT extension is being processed, then can I cancel? What should I do? And in case I don't apply for OPT Extension and my H1-B is denied during my CAP-GAP period, can I apply for OPT Extension? USCIS says I need to apply for OPT Extension before current OPT expires? But what is the definition of "current OPT" for a CAP-GAP student..when does CAP-GAP end for someone whose H1-B is denied?