Berried cherry shrimps suddenly not berried, no babies.

[TLP]

So I have 4 cherry shrimp in a 2.5 gallon dirted tank. Three females, one male. Small sponge filter, leaf debris, tiny driftwood, tons of floating hornwort, one bladder snail, one adult ramshorn and many ramshorn babies. 

One of my females became berried. A week later the other two became berried. It has been a bit over three weeks since the first one became berried. I usually check on the shrimp every day. This past weekend, I did not check on them for a couple of days. Then on Monday I noticed that none of them are berried anymore. It has been four days now, and I have searched and searched every day since then looking for babies and have seen ONE. Shouldn't I be seeing many, many babies flicking and bouncing around? It's not like it is a huge tank. What is going on? Could something have happened to cause EVERYONE to drop their eggs at once, and if so, where did the eggs go? Nothing inside the tank has changed during this time. No water changes or adding anything to the tank and such.

Confused.

[doktor zhivago]

The first instars are really tiny. They're also transparent and immobile.  I didn't notice my babies until they were in the juvenile stage

[goodjobchamp]

Ya they tend to hide super well for about a week then start to move around the tank.