Mackynz, Ambient temps are usually between 82-85F, been a little higher recently since the vet wanted me to bump them, and the last time she ate was 20 days ago.

Maegalcarwen, VERY unlikely it'd be an undeveloped egg, this came from a five month old female hatchling so I don't even think she's in the arena of being sexually mature. Also, I've never seen undeveloped eggs in BPs specifically but I have a general idea and this does not come close.
The soonest I can get a biopsy done on it is Monday so I have to let it sit over the weekend unfortunately but I'm definitively bringing it in to the vet.