Wife Tested Positive For Chlamydia

 Hey everyone, my wife and I have been together for over 2 years, married for 1. She’s had sexual partners before me, but I have not. She is 11 weeks pregnant and just took her STD test at her OB appointment, and tested positive for chlamydia. She has not ever been tested before. We just got the results yesterday and I went and got tested. My test results came back today all negative. 
I have been nothing but faithful to my wife, and she swears up and down on everything that she hasn’t cheated either. I don’t have any reason to suspect it either, I’m just confused on how this could be. Both of our tests were urine samples as well. False negatives? False positives? Any insight or possible explanation would be greatly appreciated.