I forgot to include the world seed...my bad. But from what i can remember, there was no warm ocean biome close by...but I will definitely check.
I had to wait 2(maybe 3...I can't remember) nights keeping the turtle on the sand and she laid an egg at sunrise.
I seem to have figured it out, an area of water close by was under the lush caves biome...even though it looks nothing like a lush cave.