If you are only smoking about once every 3 weeks (along with your size) I would say that you very could already be clean. The reason being....is that a one time high (when you are completely clean) ONLY stays in the system 2-5 days. Then you are clean again. Go get a test and test your FIRST morning urine. It's the dirtiest. If you pass a home test with that, then you are golden ()