Smoking pot or cigarettes wouldn't affect your medical in a way they don't directly test for opioids or nicotine else CIC would have signed consents for such specific test. These are not substance abuse test, but if you look at one of their form its requires you to disclose substance abuse history. Be mindful of that and additionally, if you smoke immediately prior to your test, it will temporarily reflect on your vitals such as BP etc so you are better off abstaining for few weeks. Hope it makes sense.