BFF wants my urine for a drug test

My bff got a new job. She’s an RN. She smokes weed (obviously not at work). She wants to use my urine for the drug test. I’m currently 5 1/2 months pregnant. At first I was like yeah sure I guess, but now I’m looking it up online and it says I could be charged with a misdemeanor. I want no part of getting in trouble with the law. Especially being pregnant I don’t want to do any jail time or mess up my record. 😳 She’s going to be pissed.

Any ideas on how to tell her no I changed my mind?