Pap test

Emma-April
Okay so I wanna ask how old do you have to be to get a Pap test done. 
I have asked my doctor multiple times about getting it done and he said I don't need to as I'm under 25 but I know a lot of my friends have had them done I'm 23 and feel it's something I should be getting done regularly. 
I only ask as my cusion just got bad results last week from here Pap test she found out she has cancer granted she is 35 and has had 3 children but it's still something I'm always worried about. 
Any advice would help. 
Thanks lady's.