You can't get hiv from oral so if that is all you are doing you have no risk and don't need to be on the medication.
If you do anal, the answer to your question is to take an hiv test to determine your status. You can go to the manufacturer's site for any medication, and find the statistics that you seem to be looking for, talk to someone at the company for the stats, or ask your pharmacist.
The point of taking Prep is to prevent hiv. If you take it daily, you aren't suppose to be worried like this. Before you went on it, they tested you, right? You were negative then?