chlamydia can be asymptomatic (25% males, 70% females) so you might not know.
in females it can lead to infertility, ectopic pregnancy and PID (major complications)
in men you'll get urethritis (painful peeing, frequency) and maybe diarrhea (in some cases. some other things happen, but those are noticeable)
also might have some dick discharge, but it's not like an explosion like gonorrhea.
it's a really quick test, just a little blood, called a rapid antigen test.
get some antibiotics and you're good to go (doxycyclin, azithromycin, or erythromycin work)