Yes, you could be charge; however, depending on the facts there may be some good defenses to your case. If it was found under your seat, next to you, or anywhere else where you could easily access it.....this would tend to make their case against you stronger. If it was found out of sight, not in your reach, and it wasn't your car......these are things that would tend to make it a stronger case for your defense. (Please do not give specifics facts about your case online, as these posts are not protected and could possibly be used against you in the future).
Have you been charged?
Also, there may be possible arguments to attack the validity of the officer pulling the car over. Obviously, a thorough review of the evidence would be needed to assess the actual strengths and weaknesses of your case.
In the end, if you are charged, it would be in your best interest to try to obtain a resolution that would keep a conviction off your record.
I hope you find this information helpful and feel free to contact me if you have any further questions about your case. I wish you the best of luck.