I Have a Drug Test Monday May 11 at 11am I Start Daytreatment Tomarrow for My Substance Abuse and Rehab?

i have a drug test monday may 11 at 11am i start daytreatment tomarrow for my substance abuse and rehab the following week i dont think i will pass what would happen i have been trying to get in rehab for a couple week and self admited myself to the hospital for the problem i was not sure what would happen