The default URL for the Pulse Web Client is http(s)://localhost:8099 or http(s)://serverName:8099.
To access Pulse with a specific host such as https://pulse.mycompany.com you will need to update the AllowedRedirectHosts in the conf/Pulse.cfg file:
AllowedRedirectHosts = https://pulse.mycompany.com
Save the file and then restart the Pulse Application Server.
You will now only be able to login to Pulse using the host.