I've Had A Partner Since March And We Have Had

I've had a partner since March and we have had intercourse a few times a week since we got together. he just found out that another partner of his was possibly exposed to chlamydia in January (not confirmed, it could just be a rumor). I test annually and was negative for chlamydia when I tested the beginning of this month. My partner is waiting to get tested. If I'm negative after 5 months of unprotected sex with him is it still possible for him to be positive?