You could try using the index function. Then you won't have to worry about escaping characters (at least in this scenario): 
my $concat = "good times and fun (times) and bad (times)";

for my $string ('good times', 'bad times', 'fun (times)') {
   # if the index function returns -1, it is not a substring
   if (index($concat, $string) == -1) {
      $concat .= " and $string";
   }
}

print $concat . "\n";

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In reply to Re: Escaping parentheses in regexps by perlguy
in thread Escaping parentheses in regexps by Tanalis

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