How long after getting chlamydia will ti be able to return to sex work?

Soon. You should become non-communicable within 24 to 48 hrs after starting treatment. Unfortunately if you have one sexually transmitted disease there is a good chance that you have more than one and should be carefully checked out. If you are in sex work why are you not protecting yourself adequately?
After negative test. Obtain chlamydia testing after antibiotic treatment. If the test is negative, only then are you no longer able to transmit the infection. In this occupational "line of work" std's are a major hazard, even with "protection in place" such as condoms.