Last time I smoked was a week ago, and I have a drug test tomarrow...what to do?

A week ago I wasnt sure I was going to have an interview but about 4 days later company called and asked me to come in for an interview and I went today (wednesday) and they required me to take a drug test within 24 hrs, I work out and have been drinking lots of water (I drink a lot of water even before I knew I was going to be tested, about a liter a day) and I was just wondering am I safe? If I drink a load of water plus some OJ to bring the color back in my pee will I be alright? Need some advice