Quick question. might sound silly. but if you have multiple partners and none have chlamidia. can it be caused just by having multiple partners?

No: Chlamydia is what is known as an STI or sexually transmitted infection and can only be acquired after having sexual contact with someone that harbors the illness. Be sure to practice safe sexual practices such as condom use or other barriers.

They might no know: Some people have few if any symptoms when they have chlamydia, some are quite symptomatic.Many would be reluctant to share that diagnosis if they had it. Having multiple partners will increase your risk, but you had to get it from someone who had it at the time.