Is coccygodynia a reason for cesarean? My bone is so deformed it might be a problem during delivery.

Might not be. If you have a good working epidural or a combined spinal- epidural. See your pain management doctor after you have your baby.
Coccyx Strain. Coccygodynia is a painful condition involving the coccyx, but a sprain or old fracture isn't a deformity requiring cesarean birth. Muscles and ligaments from your coccyx include the pelvic floor, so you can change your chances with manual therapy and exercise. See a do or pt familiar with neuromuscular/osteopathic manipulation (omt); your ob/midwife might know one, or see www.AcademyofosteopathY.O.