You shouldnt be smoking at school - you should be smoking period at your age.

If your going to get wasted and then go to a lesson infront of everyone at least do it when you can actually handle your weed.

Your head just made a guess, he didnt know it was weed [or maybe he did?] but still, they cant do anything about it as long as you've got nothing there, and even if they did drug test you nothing would happen. It's a school. They cant tell you what you can and cant do in your own time, remember, this is England and not America.

But still, at your age i wouldnt be smoking, wait for another year or two first, seriously. Your only JUST a teenager, you shouldnt be smoking. I started when i was 11 and know that was way too young, and your only 3 years older than single figure kiddies.