It's possible your head won't even touch the wheels, since I think that's the scenario you've thought up.
Many trains nowadays have those, for a lack of a better word, barriers in front of a first wagon, to actually prevent anything getting under the wheels, making the trains possibly jump and wiggle, reducing the comfort of passengers.
In other words, depending on the train, your head would get crushed and kicked off the rails before it would even make it to the wheels. And even then, no, only way to make a train derail like that would be if you had a lot of nitroglicerine in your head.