I recently dislocated my thumb. i have an mri scan booked a month away. is that too long to wait?

Sooner better: If it isn't broke then it may be okay as they can set the dislocation later but the sooner the better.

Check with your Doc: Check with you orthopod or whoever is treating you. I am sure the thumb dislocation is reduced and its splinted. Generally a dislocated thumb will not require a mri, unless you have an additional injury or your doc had some other concerns. Best advice would be to talk to your doc..