First of all, the Lakeland Nailsnail Snail is a freshwater shellfish that will not survive in a planter. What you are describing is most likely a fine drill snail/striped drill snail of the drill snail family or a sharp true pipe snail of the sooty tube snail family.

Secondly, even if you do come across a Lakeland nailsnail snail, it's unlikely that you'll be infected. Transmission of schistosomiasis only occurs in endemic areas, and the medium of transmission is water. In other words, as long as you have not been exposed to the body of water in which the infected snail lives, you will not be infected even if you come into direct contact with the shell surface of the snail.

References: my site on the pipe snail and drill snail map; national specimen data platform for the Hubei nail snail description