It really just depends. First and foremost don't carry any pot with you. I don't care if your worried about getting caught by your parents, you should never carry your stash with you outside your house, especially at school on 420. Be smart and understand that getting caught by your parents is far better than getting caught by the law.

Secondly, I would only do this if you can act straight while high because even if you don't have any on you, the fact that your wearing a 420 shirt on 420 and you appear to be high, is enough to get your in trouble, and I don't just mean by your school, although chances are if you don't have anything on you, they probably won't get the authorities involved. In any case I wouldn't risk it if you can't pull it off. But if you do make sure your eyes are clear and your breath and hands smell clean.

It really sucks living in a nation where you have to hide your true identity...