HI, I will be working for a Flu vaccination company in a few months, and this is my first time doing one of these? As an RN for 6yrs, I am nervous about this for some reason? Can you give me tips for this? I havent given many Ims, I have a few questions? Do you pull back on needle, once inserted to check for vein/artery puncturing? Ive heard dont pull back on live vaccine, some say do pull back to check? How much do you pull back? Off topic: Picc lines-do you pull back on these when flushing?