Pop up before payment in WooCommerce

Hey forum,

I am in dire need of a plugin for my webshop. The plugin is supposed to pop up right before payment, with a message that says that i won’t be able to send orders for a week. Would be awesome if it had two selections that says “OK, i am willing to wait, let me pay” and “Aaarh, i would rather wait then”

Does anyone have an idea to what i could use? Or modify to make work for me ??