Let it stay untill you either see Phorrid Fly Larvae or it explodes..........I've seen plenty of nasty Eggs turn into perfect hatchlings, so never say never untill you see either one of the above.........
Ours take at least 100 days. Most hatch between 104 and 130 days. Discoloration could be a sign of going rotten. Usually ours that are fertile are solid white with no discoloration. Good luck!
These are aldabra eggs, however it is a good visual example. The two with the small "X" on them are not fertile and the other twelve are fertile. Note the discoloration of the two that are not fertile!