if it is very emergency  then just tell him to mak a print of that  letter concerning the permission of delay. And if i was a councelor then that is a negetive impression but if the college accepts your reason then as far as i believe there should not be any obligation on port of entry. So always have an  answer ready for that like i'm going to take some fast track course or i'm already taking some of the internet courses from here and so on..... get help from the advisor they'll give u as many reasons they can because u are their source of income and one important part of this country's economy. so take it easy........