I have been short listed to be interviewed for admission to graduate school. A couple of days ago, I received an e-mail with four possible time slots, but I coudln't answer immediately because of a health problem. Indeed, a friend answered for me. My answer was a bit delayed but still on time, during the past weekend. The first slot was on monday morning but certainly, I choose the last slot to be sure I am going to be in the best possible shape for the interview. That slot is in 1 day and half and I haven't received additional information, neither a confirmation nor a plain rejection of my interview.
Should I assume that the interview has been setled and wait next to the phone or write to confirm the interview? If I have to write, which is the best way to do it? I don't want to sound like harrasing the interviewer.