Tested positive for chlamydia. today i got a shot of antibiotics instead of pills. how long will it take for symptoms to go away?

Maybe gonorrhea?: Are you sure the test wasn't positive for gonorrhea, not chlamydia? No injection treats chlamydia -- at least none that is commonly used -- but gonorrhea is treated with a shot of the antibiotic ceftriaxone. If gonorrhea, symptoms should stop getting worse within a day and start improving after that. For chlamydia, it's somewhat slower. For both, complete clearing may take a week or more.