You won't see clutches of nerite eggs, and unless one of them is female, may not see any. If you do, they'll be single light coloured dots on wood, rock, even glass sometimes. They'll fade away with time, but some don't care for how the eggs appear. You can scrub them off if you don't like them, but it's a bit of work to do that.
The mystery snail, if it is female, might lay some eggs. They'll be above water though. If you don't want them, toss them. She could have mated before you got her, sometimes females will lay infertile eggs too. If male, of course, no eggs will appear.