Any test is not showing 100% efficacy. It might happen that though you have soy sensitivity test might be negitive. it is called false negative. Your complaint suggest that you are sufferring from soy allergy. So, wihout going details in investigation, you should avoid soy containing food. Regarding the second part it might be possible that some proteins of soy will be there in semen. As semen consists of proteins and other elements like sucrose etc.