Neon Eviota gobies- breeding?

[Runtita]

I think my neon Eviotas have spawned. One has been getting hugely plump, and this evening as I watched, it (she?) hovered in place over a ledge near a cave and pooped out a 1.5 x 1.5 mm whitish oval "pillow".

 

Now I must admit that I am not in the habit of watching my fish poop, so I could not ID poop if I saw it, but I have been wondering if I had a pregnant female as plump as "she" has been getting for the past few weeks. The "pillow" has since fallen into the cave where I cannot see it. It looked too perfect and formed to be poop, IMO.

 

Could it be? How hard is it to get these gobies to breed? I can't find much info online regarding my little fishies' breeding habits. If anyone here has any experience with Evoita breeding, please share!

 

Thanks!