@burcinc-- Antibiotic shots are intramuscular, meaning that they are injected into a muscle. It's normal for there to be a mild burning or aching pain from an antibiotic shot. Sometimes the technique of the medical practitioner giving the injection may make a difference as well.
If you are getting a shot daily for multiple days, ask the nurse to alternate the area where the shot is injected. Getting the shot at the same spot every time will cause the pain to increasingly worsen.
Applying some rubbing alcohol on the spot immediately after the injection can also help reduce and prevent pain.