Scared to go to the Doctor's Office now

I brought my son to his pediatrician 3weeks ago for his routine check-up (2 year old check-up) of course that check-up didn’t come easy for us as my little one is now a big boy. Aside from the routine check-up that they normally go through, like measuring their height and weight, checking their ears, mouth, eyes and etc, this time there was an immunization included and that didn’t really sit well with my little guy. Too bad he had to have 4shots at that time but fortunately the 4^th one which is the flu shot wasn’t available at that time so I have to call them again for another appointment. Poor guy….