Who laid this egg?

[TLWR]

I closed the ducks in at 7pm last night and let them out at 7am this morning.
There were 3 eggs this morning (and yesterday and the day before).
I got home a little before 4 today and brought them out some veggie snacks. I went out with DH after he got home at 4:30. There was an egg (soft and squishy) sitting next to the cutting board I served their veggie snack on.
It's white. Ally is the only white egg, the other 2 lay blue ones. But it wasn't a hard shell.

And since it was a soft shell, do I need to worry about it - they have oyster shell (not that they eat much) and a variety of veggies given every day. I'll try to give them some higher calcium containing veggies too.
Or was this just a weird "hey gotta poop, oops, that's an egg" thing?

 

[Goat_Walker]

How old are they? I dont think you need to worry

New and old layers have their fair share of soft shelled eggs every now any then. Usually its more common for new layers to have their few dud or misfit eggs but its not uncommon for older ducks to lay them as well .

 

[karbear]

My five month old Pekin, Wilma just started laying and her first few were very soft. One of them was a long soft egg and my son "disected" it and there was a hard normal egg on the inside. The last three eggs have been normal with a day or two in between. Very eggciting when they start laying!

 

[Snakeman]

I've had new layers give me eggs with just a membrane, with a weird nipple at in end(one was even leaking out of the nipple), eggs as small as a nickel and eggs that are just plain odd in shape and or size. In my experience, no single duck has laid more than 1 or 2 mutant eggs. It all sounds normal to me.