1night stand 6months ago. I found out today the girl has chlamydia. She had partners after me. I have no symptoms. Is there a chance I might have it?

Yes. Get treated. It's easy. Even the test can be done with a urine specimen. Males infected may not be symptomatic.
Yes. Up to a half of women and a 3rd of men are without symptoms after infection. She may have been infected when you were exposed & never found out until it progressed.