if you haven't noticed little con fry swimming in your tank by now, its a good bet the eggs were bunk and eaten by the parents or other tankmates. happens now and then, moreso when starting the breeding marathon.
I've been in the hobby for 22 years. The only sex-changing fish I can recall from the top of my head is that saltwater one. Please correct me members, I believe its a wrasse or some sort of parrotfish. Dominant males turn into colorful females. Again, this is coming from the top of my head, please correct this info....
As for Cons changing sex, I have never heard or witnessed of any such experiences.
i believe the majority of sw reef fish, like anemonefish, can gender bend at certain points in their life.
other fish are full blown hermaphrodites, like salmon, and can spawn at will with each other.
not too sure about convicts..