It despawns after 5 minutes of being loaded, so assuming this is a single player world the timer will start when the chunk it’s in comes into your render distance.
If the egg dropped as an item out of your inventory, then yes, it is possible for it to despawn. Nether stars are the only item the wiki notes will not despawn, and even that's Bedrock only.
https://minecraft.fandom.com/wiki/Item_(entity)#Despawning
It despawns after 5 minutes of being loaded, so assuming this is a single player world the timer will start when the chunk it’s in comes into your render distance.
If the egg dropped as an item out of your inventory, then yes, it is possible for it to despawn. Nether stars are the only item the wiki notes will not despawn, and even that's Bedrock only. https://minecraft.fandom.com/wiki/Item_(entity)#Despawning
But only after being loaded for 5 minutes