I've had 3 root canals in my life and everytime the next day i have a very sore throat, fever, and very sore glands why is this ? thanks in advance

Infection?: Perhaps each time the teeth involved had accompanying infections which caused the symptoms that you describe, rather than the root canal therapy procedure themselves.

Another reason: These are not common symptoms after root canal therapy. Fever related to root canals only occurs with infection and swelling . The same w swollen nodes. A sore throat also is not a normal sequel. Perhaps you have some sort of allergy to latex used for the rubber dam. Discuss these symptoms w your endodontist!