Just diagnosed with chlamydia

Okay, so I had my annual appointment a few days ago wit my gyno. & I just got a call on Friday saying I had tested positive for chlamydia. (I didn’t know until I got the call because I had no symptoms) I told my partner, and he got tested himself, and he tested negative. I only had sexual relations with him for 2 years & Same with him... & I know he hasn’t because we’re with each other every day except when we’re at work (I pick him up to and from work) so I’m confused how I even got it ?? I’ve never had a std in my life... is there another way I could have contacted it ?? I’m 10000000% positive I only had sexual relations with him and me and him both Are 100000000% in the only one he’s slept with... anyone else ever contracted this ?? I’m freaking out...