Missed the acknoledgement date for my electives

Damn, just realised that i had missed the deadline to acknowledge my electives. That means i only have 15AUs worth of subjects registered for this semester. What the hell.... Just emailed one of the prof to see what he can do to help....But i guess his answer will most probably be: "wait for the add/drop period and try again". I'm supposed to register for 23AUs now only 15AUs..that means my schedules have to be pushed back for 1 semester [worst case] or i have to overload other semesters. Shall keep u guys updated