How do you get chlamydia if your partner never has had it but you got it how could you contracted if he’s only had sexual intercourse with you and that nobody else
Chlamydia: How do you get chlamydia if your partner... - BASHH
you could have had it for a while, from a previous partner. You don’t say if you had one before him. I don’t think it’s possible unless one of you have had sex with another person.
Without more details it is hard to say , like for instance why you got tested, symptoms etc. remember chlamydia testing has small false positive and false negative rates - so your test has a small chance of being false positive, and his test of being false negative. It is better to treat both people if one person has had a positive result , regardless .