Infection

I have a question .. Its been eating me up . I went to my GYN last week and got my results back and she said I have chlamydia I've been looking up different ways of how I could have got this I have had one partner for about a year now and I have been faithful and he is the only one that I have been having sexual intercourse with. what is another way for me to get chlamydia is it from him with another female or what and also I have not had any symptoms like the nasty discharge or anything like that so I thought I was clean but recently he fingered me and gave me a little small cut inside my vagina could that be another reason? Is that even possible . i keep having this thought in the back of my mind that he cheated thats how i got infected ..