I own firearms, and I have a concealed carry permit as well. I carry my gun on me everywhere I go, that includes when I have marijuana on me, with my medical permit.
A police officer cannot dissarm you if you have a concealed carry permit, unless you are breaking any of the laws that revolve around carrying a firearm, or any law that has to do with firearms.
In other words, guns have their laws, and our medicine has its own set of laws. Know the laws, and stay within them and you will be fine.
A medical marijuana permit doesnt give you the right to possess, it only gives you a defense against the law. That is why you must stay within it, because they are just hoping you step out of line so they can bust you.