At this point in time i have done no breeding myself, but i will repeat what i have read and heard.
Sometimes, female ball pythons can become egg bound. This occurs when she is too small to pass the eggs (ie breeding at too small of a size), the eggs are just too big (fluke thing that happens in all species, the offspring are too large. think a male great dane breeding a Chihuahua, conceiving and then trying to gestate or even birth those pups ). In order to fix this, a vet or owner will pierce and aspirate the contents of the last egg, flatten the shell and massage it out of the female. This situation may also require surgery. The eggs will die and start to decompose which could lead to an infection, etc. This information may not be 100% correct, but from what i understand about how and why egg binding would happen, its the best of my knowledge.