I would caution doing a self PrEP program yourself. In the US, you need medical monitoring. First, you have to make sure you are HIV- before starting to take it. That means taking both the normal antibodies oral test as well as the blood test to check your RNA count. Second, it takes time for Truvada to become effective (here in the US it is recommended you take it for 21 days). I know there are studies for short term use, but that still means loading up with Truvada a few days before and continuing using it for a few days afterwards. You should also be tested for the other std that Truvada does not protect.

Finally, the most important reason why you should have constant medical monitoring is because Truvada affects your kidneys. You have to check your kidneys are operating within the safety limits on an ongoing basis.