I have Arcmap 10.3.1, was ArcPro included in this version?
If you are with an organization, go to My Esri and check your organizations download section.
10.3 is a tad old as well, so probably not
ArcGIS Desktop 10.3.1 was released in May 2015 and ArcGIS Pro somewhere in February 2015. So perhaps you do have access to it, although you might need a named user and if you are not on maintenance you will probably don't have one. Best to upgrade (if possible) and have access to the latest version of the software and if you run into problems at least you will have access to support. ArcGIS Pro up til version 1.4.1 has already be retired: Esri Support 2.2
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