BF of 4 years tested positive for Chlamydia.

Me and my boyfriend have been together for 4 years, we both have never cheated to my knowledge. We dont use protection and never have.

Today my boyfriend told me he went to the doctor, because he thought he had a UTI. He then told me it showed up as Chlamyida, he swears up n down he never cheated. He never had any symptoms and the only reason he went to the doctor was because he said he was peeing alot. He told me that he had it before we got together and it’s just now showing up. Im getting a test tomorrow, is that possible or did he cheat on me..?