Yes, you would get a fecal float at the vet's office. Collect a fresh sample of her droppings in a little baggy and take it in.We don't think it's leaking from her butt. And it literally looks like someone cracked an egg in the nesting box. Her abdomen doesn't seem any larger than normal.
How do we get a fecal float? Vet's office?
It's good that she's not leaking and it sounds like there is at least a membrane covering the yolk.
It can be very hard to expel a soft shell membrane, so giving her the Extra Calcium Citrate with D3 daily will hopefully help firm up the shell and help with contractions so she can push the egg out.