i think that is the protocol, as generally PEP is recommended with an exposure to an hiv positive person, but if you are in doubt, then go ahead and take the PEP. it's your choice. i actually recommend you do. better to be safe than sorry.
you need to know that perosn has hiv+?
it's worth considering - you did have a risk here. is the person you had sex with confirmed hiv+? for peace of mind, it would be a good choice to take the PEP and follow up with hiv testing. PEP would drastically reduce the likelihood of infection taking hold