Husband DOES have chlamydia

My husband said he didn't cheat, that he probably has it from 5 years ago when his ex wife gave it to him. back then he took pills for two weeks then had unprotected sex a couple times after that. And he's claiming that he thinks it stayed with him because of the unprotected sex he had afterwards with the girl he dated after their divorce. Let's just assume I believe him, can that really happen? Then would it just stay there till 5 years later when he started peeing blood and got tested to find it again? Or is it wishful thinking because I don't want to believe he cheated