I'd be very surprised if HRT affected your test results. When blood or urine is collected, the sample is sent to a lab which will perform whichever tests are requested. Some tests are performed with chemically treated strips of paper which will change color if, for example, cocaine is present. Usually, the labs are only looking for illicit "recreational" drugs, marijuana, cocaine, heroin and it's derivatives like codeine, oxycontin, etc. Methamphetamine is also commonly tested for. Sometimes screening is also for alcohol. Since all of these are totally different from anything used in HRT, I can't see how they would show up. Estrogen will be found in genetic women, and to a much lesser degree, non-TS males, and spironolactone is often prescribed for several common medical conditions.