Knowing if Oracle account has been locked?
If you don't have admin rights you probably won't be able to troubleshoot the issue without your DBAs. 
Some hints for troubleshooting (again, with your DBAs)


If the user is locked after some time (and not multiple times a day) the PASSWORD_LIFE_TIME in the (default) profile for your user might be the culprit.
If the user is locked randomly and you don't have something fancy like auditing enabled, you can look at your listener.log and check if there are connections from hosts you  aren't aware of. Often some web service or workstation with old credentials caused user locking at my place.


If you don't have any access to the server's log files and/or the admin views this issue is hard to resolve. Team up with your DBAs