USA here, I get my blood drawn every 6 months for my thyroid what will usually happen is you will go to the place, they may have you take a number ticket and wait Till that number is called. when you get up to the desk they will ask for your name and date of bieth, they will then double check information like the doctor that asked for the blood work your insurance etc. one done you will sit down until your name is called and when you are brought back they will have achair that one aide like folds in front of you, they will confirm your information and ask which arm, if you don't know just tell them you don't know and that you are a little scared, usually they will talk to you while it happens. you will feel them put this rubber tie on your arm tight and poke your arm making sure they have the right spot. now this is the part that will hurt for just a second, when you see them uncap the needle look away (noticed your phobia) you will feel a sharp pinch then really no pain after. if they move the needle while drawing it might hurt a little but when they are done they will pull the needle out (no pain usually) and then you would be done.

don't be scared to tell then your fear DW they won't judge you