I recently went to pain management and they did a drug test and it showed I tested positive for Oxycodone. I only take hydrocodone and do not understand how this happened. The pain management clinic refused to take me as a patient because of this. I am now being referred to another clinic and am worried this may happen again or they are going to see in the records from the other clinic this positive test... My question is, Is it possible this could be a false positive?

Nope... With as many random tests I've had over the years (nearly 30 years now, all job related).. I've never had a false positive once... or known or heard of anyone else who has.