Did he cheat??

This is really hard for me to write, but I want answers. When I was pregnant with my daughter I’d tested negative for chlamydia for the whole pregnancy. Well when I was about 30 weeks I caught Covid and then noticed bad yellow discharge so I went to ER, came back positive for chlamydia. I’d never slept with anyone else but my Husband and we’ve been together for 3 years. He swears up and down he did not cheat on me. He didn’t get tested for it, or take the treatment for it. I did. I tested negative before I gave birth and I’ve continued to test negative. My question is, is there a way I could have got it without him have having sexual relations with someone else? We’re married but this whole situation has had me over thinking, anxious, and mentally exhausted to where I’m ready to leave…I had a gut feeling back then that he maybe could have done it, but we have life 360, so I know he’d only been going from work to home and vise versa. And wouldn’t I have gotten it again if he didn’t take the treatment? Help an anxious mother out.