How to check return status of parallel branches in jenkins pipeline
You may want to try the Join plugin. Some more details about this plugin (from the linked page):


  This plugin allows a job to be run after all the immediate downstream jobs have completed. In this way, the execution can branch out and perform many steps in parallel, and then run a final aggregation step just once after all the parallel work is finished.
  
  The plugin is useful for creating a 'diamond' shape project dependency.   This means there is a single parent job that starts several downstream jobs. Once those jobs are finished, a single aggregation job runs.


For more details on that, refer to my self answered question about "Why trigger something remotely (using Jenkins) and then just forget about it?".