... but in my personal experience, that's a poor assumption to make, because:
1. Not all STI's are bacterial infections
2. Many bacterial infections are resistant to specific antibiotics, including Amoxicillin. You will need to get a bacterial culture to get it identified, then have a doctor prescribe the antibiotic that is most effective in treating that specific infection.
3. Taking an antibiotic when you do not have a specific, diagnosed condition to treat is BAD. That's why you doctor does not prescribe them all the time, like vitamins.
Instead, go get a test for ALL known STI's now - not just HIV and a few more - ALL. Then set up a regular schedule to get tested on an ongoing basis. Use a clinic, independent lab, or other (online) service if you don't want to use your current health plan provider. The cost of frequent testing is MUCH lower than the cost of treating an STI late in the game. And it's much lower than the cost of a divorce as well. And it's much lower than the cost (and effort) of finding new providers if your current ATF('s) black list you for passing them an STI.
I do what the porn industry does. I get tested at least once every 30 days. In fact, I use the same lab the porn industry uses.
Life is good
The Cat