It really depends on your situation.
If your only concern is what happened on Jan 1 and you have no symptoms its usually best to wait 2 weeks as most cases of chlamydia would show up by then. With the blood tests (syphilis and HIV) it can take up to 3 months to get a final result, but most tests would show a positive result by 6 weeks.
Have a look at our “STIs at a glance” chart, it provides information on how long you need to wait before getting tested (window period).
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