Will multiple conditionals slow down page load?

The answer is no but just to put your question into perspective I tried the following code. 1.5 million ifs.

$start = microtime();
$count = 0;
while(true) {
    $count++;
    if($count > 1500000) {
        break;
}
}
$stop = microtime();

$total = $stop-$start;
print "Total time:$total";

0.16 seconds