Yes, the 12 issue arc for this Lovecraftian nightmare did end in April... but the full hardcover collecting all issues isn't out yet. So as far as I'm concerned, it's still ongoing!
Providence is Alan Moore's (yep, the Watchmen guy!) follow-up to the Neonomicon, and if you read that series, you know to expect some disturbing things. This isn't one to let the kids pick up unless you want to answer some very awkward questions about what the naked woman is doing with the fish person.