I have heard that it can be positive for a year, so the best thing you can do is call any Dr's office anonymously and ask them. They will give you the answer for sure.
No it should not show up in a drug test. I hope now that you have stayed off it for a month you will from now on. That drug will ruin your life.
Hair follicle testing goes back 90 days. Cocaine use will show up. All drugs stay in your hair indefinitely.