As it is impossible to know what happens to us if we black out, the only way to know for sure if you were in contact with an STI is to test.
You are right that the symptoms you are describing are not typical of an STI but the increased need to urinate maybe be related to a mild urethral irritation and this is a symptoms of an STI.
If you are at risk Chlamydia, you must also assume you are at risk for gonorrhea and Syphilis and as these do not always have symptoms, testing is the only way to know for sure. If you need help finding a testing clinic in your area, use our ‘Find a Clinic’ function (http://smartsexresource.com/get-tested/clinic-finder). Since this happened a month and a half ago your tests would be very accurate at this time but a follow up syphilis test after 3 months is recommended.
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