Its difficult to know the exact chance of something passing to you as there are so many factors involved. For example, do they even have an STI.
As most STI do not show symptoms its common that your sex partner may not even know themselves if there was an STI unless they go for regular testing.
It’s great that you are using protection all the time as that will really reduce the chance of something passing. It also sounds like it was a brief exposure time.
If you were going to have sex with the same person again it would be good for both of you to go for STI testing, if all the tests were negative and both of you had not had any other risk in the past 3 months you would be good.
As it was a one night stand I am unsure if you plan to have sex again or if you have the person’s contact details or feel comfortable asking them to go for a test. In these situations, its best to do your own STI test that would cover the window period. For example, most gonorrhea and chlamydia would show up in a urine test by 2 weeks, blood tests like syphilis and HIV will usually show up by 6 weeks but a final test is recommended at 3 months just to make sure.
Given this I would wait 2 weeks before going for a test and then doing a follow up blood test at 6 weeks or 3 months. If you get symptoms before you can always go to the clinic sooner. Also, the health care person you see for testing will know your details so can give better info on when to test to cover testing window periods.
With the type of sex, you described I would say out of the STI tests we test for chlamydia would be the most common STI to pass in this situation as it is common and usually shows no symptoms.
Let us know if you have any more questions or concerns.