Create Automated reminder based on the days out from deadline

I am sure that someone else has a similar problem, but I surely cannot find any solution to this...

Running SharePoint 2013. In my request form, there is a date when the tasking is due, and a field where the decision can be set to "pending."--obviously different fields.

What I would like to do, is to send an e-mail reminder about the event starting 14 days out, and each day thereafter until: 1) the decision is no longer pending, or 2) the date has passed.

I am completely new to SharePoint, Nintex, and Workflow, so my level of comprehension is limited. I understand Excel, but this is obviously not the same. Any assistance is greatly appreciated.

-joe