I am assuming you live in Michigan. Possession of under an ounce can get you up to 90 days in jail and 100$ fine. It is a misdemeanor. This is from NORML. I would be incredibly surprised if you went to jail. If you do it will be for a day or two but I don't think you will go unless you have priors. Do you have any priors? If you did go to jail it would likely be for a day or two. You will probably have to pay the fine and may get probation. Keep us updated and good luck man.