With regards to monitoring a security clearance, there really isn't much you can do other than noting when the various background investigations will need to be redone so you can keep your CV up to date as once the background investigation expires it loses any value when it comes to job hunting. You don't get any notification when things lapse and if you interview with someone saying that your investigation is valid and that is not the case they may not want to keep you around for a reinvestigation.
When you leave the FSO may be able to provide you with a print out saying when the relevant investigations were performed for your records.
From your comments to the question it sounds like you really need to be talking to the FSO and having them find out what is going. Likewise, if you are in a certain field then that may help as different agencies can help sort things out better for their own people than trying to take the general approach to the problem.
In summary, if you are currently employee by someone you should talk to your FSO and work closely with them until the issue is resolved. If you aren't currently employed by someone then you are better off just indicating when the relevant investigations were conducted as a lot of issues might get cleared up just by changing sponsors.