Many people seem to think that there is a law that prohibits a police officer from following you up to certain distance. The short answer is NO, as long as the officer has reasonable suspicion a traffic violation has occurred for example , swerving, improper lane change, speeding, etc..he will can continue to follow you. This may occur for a variety of reasons: traffic flow, type of violation occurring, safety.
If you are being followed just keep calm and drive as you normally would in accordance with the law. If the officer makes the determination to execute a traffic stop, once you see the lights or hear the sirens, pull over to the right in a safe manner. Guilt is not admitted by pulling over, it is the law.
The important thing is to remain calm and follow the officers requests