That's a tricky question. You are right that you are doing nothing wrong and should not be bothered. However, your lease agreement states that you can be evicted for using illegal drugs, and under federal law, marijuana is still illegal. My opinion is that you should be ok. You are not violating state law and recent case law has been interpreted to mean that local law enforcement is required to enforce state law and not federal law. I would argue that it applies to local landlords and local courts as well, but the law is still a little cloudy in this area.
I hope that helps. If you have any other questions, feel free to give me a call