Little Black sacks....Need an ID

So, just got my tank on the 13th, biocube 29, completely stock as far as filtration, light etc. with the exception of adding 2 strips of LED that the hood provides slots for. I have 30lb live rock from established tank and 2.5" live sand. I have a clown fish, coral beauty, a coral banded shrimp, several snails and hermits and several small lps corals. Have done essentially nothing to the water since setting it up aside from adding a bottle of stuff made by instant ocean the LFS recommended before adding the fish. First water change will be done tomorrow (a little over 2 weeks, but haven't had a chance yet, too busy).



Here's the Q: I just noticed what appear to be little sacks in several places attached to my live rock. They are black/grayish in color and almost opaque to the point that I can see what look like little white specs of something in them. The only reason I'm concerned/curious is because I've never noticed them before and I stare at the tank alot haha. Idk if they are eggs or what? I'm a total beginner.



Thanks in advance for any insight or input!!