Can Zantac 150 show a false positive for methamphetamines?

Today I tested positive at my probation office for amphetamines. I have not been using any illegal drugs ,of any sort. I have only taken prescribed Oxycodone, gabapentin, Zantac 150mg, and Claritin 24 hour. Does anyone know what has happened to cause a false positive. I certainly will find the culprit to this massive problem I now have. What an awful 30th birthday present.