my son completed his medical but when we checked it said he had to take another urine test. He worked out alot (is playing football for academy) and takes alot of protein, but his mother an i are concerned that there may be something wrong. Is this a normal procedure, to have them retake a urine test, and should we worry that there may be some other medical problem? he never fasted or did anything before his last test, they said he didn't need to when i called and set appt. so he drank a shake and worked out before he went!