Chlamydia positive but my boyfriend isn’t?

I recently got news that I tested positive for chlamydia, however my boyfriend tested negative about a week ago & we’ve had unprotected sex plenty since february up until the 31st of March. how is this possible ? i’m afraid he suspects I cheated on him but I never have..

(EDIT: These comments are making me overthink & I forgot to mention I tested negative a year ago & have been with 3 others before him AFTER testing negative)

UPDATE: The chlamydia was only in my throat. We never really had oral sex & I know exactly who I got it from now because there’s only been one person I ONLY had oral sex with before him. My boyfriend & I got tested & treated together. All the shade has cleared lmao.