How to check if URL has http:// or https://?

You can use

$isSecure = Mage::app()->getStore()->isCurrentlySecure(); 

or

$isSecure = Mage::app()->getFrontController()->getRequest()->isSecure(); 

Source here.

You can use below as another solution:

if (Mage::app()->getStore()->isFrontUrlSecure() 
    && Mage::app()->getRequest()->isSecure()
) {
    // current page is https
}else {
    // current page is http
}