Endler Female Stillbirth

[Mza36]

i purchased some endlers a few days ago from my lfs and noticed while acclimating them that one of the females seemed to be giving birth. now a few days later the female still has the protrusion but seems otherwise healthy.im also wondering if it could be an eggsack but i dont believe this is a trait of live bearers.

Any suggestions as to what to do?