this is extremely unlikely unless you have a mission. If not then the time guards would have stopped you already
Hmmmm... here we have a little flaw in your story Chrono boy...
How often do these Time Guards check the timeline for 'violations'?
Consider this scenario...
Time Travel is invented in 2500.
The Time guards check the time line every 3 months.
When you go back from the future, 88 scans by the time guards will detect your journey.
Do you have to identify yourself each time?
See the problem?
Now consider this one...
Time Travel is invented in 2500.
The Time guards make one scan. A catch all if you will.
They will suddenly, at a single point in time, become very busy with all the traffic coming through this bottleneck.
By your own admission, the time line can be changed. Thus preventing one time traveller may actually cause another traveller in the future to take his place.
The Time Guards would be busy for an infinitely long time.
There is also the problem that a time traveller from your future could return to 2501 without being detected.
I would be interested to hear exactly how this time detection works for your time guards.
James