I've Only Had Sex With One Person And He's Been

i've only had sex with one person and he's been tested and all have came back clean , we recently got pregnant and when the doctors came back with the test result it was positive for a baby, and for gonorrhea.... my boyfriend has no symptoms and has only been with 3 girls. his last was a virgin and he was with her for 2 years, can someone explain how he can be clean and i'm not? i've experienced burnng with urination since the first time we had sex in november and he used a condom then, but ever since then it's been gradually increasing and we haven't been using protection. again this is the first person i've been sexually active with.