Well, my first injection was yesterday, and it was entirely painless, I was so happy it was so easy (I did a quad shot). After putting everything away, I realized I was an idiot because I did everything right except I forgot to aspirate, it was definitely because I was nervous.
However, what if you do aspirate and blood comes into the syringe? Do you change needles or completely discard the syringe and use a new one? I am assuming which one it is, but assumptions are the mother of all fuck-ups. Just want to clarify what is considered sterile technique.