Amox won't likely cure any STDs, but may have helped prevent you from getting one. There is no way to know if this happened or not, though.
Doxy would cure chlamydia (which is really unlikely to happen with oral), but wouldn't cure gonorrhea. It also wouldn't cure herpes, which is a virus, or syphilis at that dose.
Herpes and syphilis wouldn't cause the symptoms your gf is experiencing right now, but gonorrhea might.
There are some problems now. You've taken a boatload of antibiotics, so if you test now, you might get a false negative. You can test, but if you get a negative, you can't trust it for a few weeks after finishing your last antibiotic. (This is why self-treating is never a good idea. I understand totally that you needed the amox.)
The symptoms your gf is experiencing can be caused by so many different things, from ovulation to an infection to an ovarian cyst. The only way for her to know is to get checked.
The chances that you got anything from a "brief" oral exposure are slim, but it could happen. (I don't know what "brief" means to you - a few seconds? A few minutes? 10 minutes?) Please keep her health in mind, and be honest and let her get tested for what she needs to test for. If gonorrhea goes untreated, it can cause long term (think lifelong) consequences.
1) It is possible that you gave her stds. But very unlikely
2) the antibiotics you took may treat some stds
3) it would be prudent for you and her to get tested at the appropriate period