First pap?

Nyla • Living 20 and carefree in the big LV
So I'm 17 and a virgin and I want to get on the depo shot because my periods are really bad and my mom made the appointment and they told her that I need to have a papa near first and I'm super scared and I don't know why. What are they like? Do they hurt? Should I have to get one? Is it true that I need one for the depo shot?