apple snails, given being the same species (such as two diffusa or two cana) can and will breed at will. The good news is that if they do lay eggs, it will be OBVIOUS. Let them set for 24 hours, pull it off. Freeze for 48 hours to make sure all embryos are dead. Dispose as you like.
Very important to never just toss an egg sac into the garbage. If even one hatches it can wreck havoc on the local ecosystem.
However Apple snails need a male and a female to reproduce. A fair word of warning. Females from a pet store tank that has both males and females, may already have mated with a snail. They can store sperm for upwards of 6 months.
IME when they start to lay eggs, they will do so constantly. I was left with a clutch ever 2 or 3 days.