There is almost a zero chance you got anything from this, and you absolutely don't need the antibiotic. Taking that when you don't need it only creates antibiotic resistance.
The only things you might be at risk for are syphilis and genital herpes type 1. If she didn't have a visible sore on her mouth, the chances of either are astronomically low. If you've ever had a cold sore, ever in your entire life, you have hsv1 already, and can't get it genitally.
Syphilis is uncommon in most places. Wouldn't even worry about it.
What I would worry about is that these places cause you guilt and anxiety and you continue to go back. You need to figure out why you do that.