I just made a smoothie with creatine, even though it's not necessary I figured why not, so I'm drinking it now, not sure if there will even be any left in my system come the morning.
It takes 3 days for creatine to metabolize into creatinine - the actual constituent (along with SG) being tested in the dilution check. Therefore, creatine-loading should been done 3 days prior to the U/A.