How can you call the teacher when the alarm clock doesn't go off and you are absent from school?

Teacher: I wrote my homework too late last night and forgot to let the alarm clock go off. The alarm clock by my bed didn't go off this morning. I slept so hard that I woke up to see that it was nine o'clock. I went to school and missed the school bus. I was in a hurry, so I had no choice but to skip class for one day.

Teacher, I'm afraid you will miss me. I teach myself at home, and the teacher can rest assured.