In the state of florida if you fail a drug test for your job can i take another 1?

I've been working at my job in the state of Florida for about 10 months almost a year and today the decided to do a random drug test. I do smoke marijuana and have recently had 2 teeth extracted, I've been taking lots of ibuprofen, loratabs, amoxicillin, penicillin & promethazine (phenergan). I heard that these meds. can cause false positive test results. Is this true and if so when the results come back can i tell them and take another drug test? is that my right? what should i do or, what can i do?