Upgrading Nintex versions

Hello all, 

I'm getting ready to upgrade our Nintex version to the most current one. We're using SharePoint 2013 on-prem. We're a few versions behind. I'm just curious to know if there's anything we need to look out for when upgrading our Nintex products. 

Current versions: Nintex Workflow 2013 (3.1.7.10)

                             Nintex Forms 2013 (2.9.1.20)

Will the upgrade affect the workflows and forms that were created on older versions? 

Will i need to re-publish the workflows or forms?

We have a lot of workflows and forms published and i don't want to break any of them with the upgrade.

Is there anything i need to check before upgrading? 

Thanks