Looks to me like a Strombus maculatus, and yes, in the Conch family. I have hundred in my aquarium, and at some sites, they are actually sold for the trade. They're extremely benificial in aquariums. This is copy and pasted from another site who sells them:
Species: Strombus maculatus
Taxonomy: prosobranch gastropod mollusc
Maximum size: 1/2 inch
Diet: diatoms, algal films, low turf algae
Method of production: 100% Captive-Bred at Indo-Pacific Sea Farms
Benefit to reef tank: algal grazing and egg production*, cyanobacteria control**
Number of egg capsules produced: 2-4 per spawning event
Number of eggs per capsule: 4-10
Time to hatching: 3-4 weeks
Type of development: benthic, direct (no planktonic phase)
Available in the Mix and Match Special or the Reef Tank Tuneup
I'll attach some pictures of mine (both top and bottom of the snail), and you can see if yours resembles this.
Graham