Rabies tention. I get rabies in future?

When its too late to start rabies vaccine after exposure??I have read that as rabies has a long incubation period so we can be safe if we take vaccine before the development of symptoms..i.e if taken in incubation period then we are safe...If the virus enters the brain then symptons occur so if we take vaccine before the virus enters the brain then we are safe,is it so??..Now my case 2 dog had bitten me little bit in 2001-2002 but at that time i have not taken vaccine,Later after 6-7 years i got worry and took 3 vaccine in 2008..Total i have taken 17 vaccines from 2008-2012..But the dog bite of 2001-2002 does not get out of mind,always i used to fear that i may get rabies in future..and its effecting my life badly..Can i get rabies in future??If yes then give me a way to protect me or if their is no chance of getting rabies in future then give me sureity..I cant live in worrie n Fear of Dying with rabies..So please help me out of the problem and depression.