Nobody is gonna tell you the truth. Even if she got tested clean at the time she went and test, it doesn't mean anything cuz there are chances she got infected by someone the next day. It is best you check regularly every 3 months or so if you hobby often. Some STI have no symptoms and you might not even know you had it.
Here is what you should know........
Your chances of getting a STI can depend the sex you're having and prevention strategies you use. Learn about the chances of getting or passing an STI using these tools.
smartsexresource.com