Because they are afraid they might be reprimanded by their superior for being away from work without due notice, most employees resort to using doctors notes which are downloadable online. Well, if you really got sick or have a valid reason to justify your absence, there should be no problem at all.
But if you were not given permission to skip work, then you really need to show a doctor’s certification before you can come clean before your employer. In using a doctors note, make sure the notes are well composed and written in professional lingo.
Also the certification must be applicable such that the reason indicated must be believable. The format of the notes must also conform to the standard letterhead document of physicians. Be careful with the printing and there must be no alterations in the text. You can affix the signature yourself or ask someone else who has stable handwriting to put the doctor’s initials.