In your previous post, you state you had unprotected sex, but not with a know HIV-positive person. If she wasn't HIV+, then you were NOT exposed to the virus. PEP is generally used in cases where a person was at risk with a person known to be HIV+. It carries its own side effects in addition to being expensive.
If the person was not known to engage in high-risk behavior, or if you do not live in an area with high HIV prevalence, it's likely not warranted. However, this is a decision best made between you and a physician.
If you know for sure that you had a legitimate exposure, yes.
Did you have unprotected vaginal or anal sex with a known hiv positive person?
Or the above mentioned sex with someone that clearly is high risk. Like an IV drug user.
You should discuss this with your Dr.
What was your risk?