Help Phone call options

[Vinsanity93]

I might be a little late on this but does adding another person during a call cost extra? I just found out by pressing menu during a phone call lol. Would I be charged for a 3-way or conference call for doing that?

BTW what does the flash thing do (The 1 that has a phone with arrows pointing in opposite directions)

 

[Cubanjinx]

No it doesn't cost you extra and flash is how you you switch between convos if some one is on hold