Should you run DBCC CHECKCONSTRAINTS regularly?
From Microsoft documentation:


  Checks the integrity of a specified constraint or all constraints on a
  specified table in the current database.


You only urn this after repairing a database and against the objects with constraints to confirm those constraints are still valid.

Quote from The Accidental DBA (Day 13 of 30): Consistency Checking by Erin Stellato


  CHECKCONSTRAINTS is a command to verify that data in a column or table
  adheres to the defined constraints. This command should be run any
  time you run CHECKDB with the REPAIR_ALLOW_DATA_LOSS option. Repair in
  DBCC will fix corruption, and it doesn’t take constraints into
  consideration; it just alters data structures as needed so that data
  can be read and modified. As such, after running repair, constraint
  violations can exist, and you need to run CHECKCONSTRAINTS for the
  entire database to find them.