Every Saturday my alarm works at 6:20 am with strange sound that is not recorded in my iPhone6 plus (64GB). I’m sure I didn’t set this alarm at all.

Every Saturday my alarm works at 6:20 am with strange sound that is not recorded in my iPhone6 plus (64GB). I’m sure I didn’t set this alarm at all. It still works even after I updated iOS to the new version 11.0.3 Note\ This problem starts after I restored my iPhone because it’s suddenly stopped working (I think the reason was no more space.. I restored it and it works good now only this problem appears) I hope I wrote enogh information. Best wishes Rawaby