What precautionary measures can be taken after having unprotected sex?
If the unprotected sex happened less than 72 hours ago, you should visit a HIV clinic to get a post-exposure prophylaxis (PEP) treatment immediately. If taken within 72 hours of exposure to HIV, PEP can stop the virus from mutating and spreading through your blood, therefore reducing the chances of you becoming HIV positive later. You should also get yourself tested for HIV and other STDs at least after 10 days after the exposure. Other than these, I do not think there are other ways you can reduce the risk of getting HIV if you have been exposed to it.