Is This A Valid Masterlock Combination Is This A Valid Reason For Missing Class?

Is this a valid reason for missing class? - is this a valid masterlock combination

Start an antidepressant that makes you really sleep so accidentally sleep through class?

For as a rule, my alarm clock, long before they actually get, but I can not remember playing my alarm and go outside. I have not slept, not waking up in the class I think twice last week, and usually up to 4 clock. It's really strange missing all the classes and I do not know what to say.