Glad your son did so well!
My daughter has gotten blood drawn every other month since the age of two (almost four years). She also gets two injections each week. She actually begs to get blood drawn instead of one of the injections. When she first started getting poked with needles, we tried emla, but she hated it. She didn't like the feeling of it on her skin. We also tried ice, which she also hates.
There is a thing called a Buzzy (you can google it - buzzy needle pain management or something like that). It's supposed to keep the child from feeling the needle. We tried that with one of my daughter's shots, but because the medication burns as it enters the skin, the Buzzy didn't work. She also felt the needle for her other injection. She's been poked with needles so often that I don't think the Buzzy was right for her, but for a child who has an occasional encounter with a needle, it might be a good option!
At my daughter's last blood draw, she watched a teenager go in by herself , and so she said she was going by herself too. I asked if she was sure, and she said 'yes' so my husband and I watched her go in and do it by herself (get her sleeve rolled up, put out her arm, tell the phlebotomist that she doesn't like bandages, etc.). It brought tears to my eyes that my five year old could be so brave and mature to handle it all alone like that. Kids are amazing!!