I remember the first time I got liverock, I spent HOURS looking over my liverock finding all sorts of stuff on it. Even 6 months afterwards, I still found new stuff amongst the rock as some of the tiny critters reached a size that I could actually notice them, and others breed enough in my tank that there's enough to spot.
I have the mantra of innocent until proven guilty unless you see it salivating over your corals
Have fun watching the rock