将内容插入WooCommerce循环

I have a 12 product per page loop and I am looking for a way to insert some content into the existing loop without breaking it, between product 4 and 5, between product 11 and 12 and so on.

Is there any if function like

if (loop=4){
    //get some content
}

It is stored in the global variable $woocommerce_loop so your condition would look like

// do something every 4th product
global $woocommerce_loop
if ($woocommerce_loop % 4 == 0){
  //get some content
}