I have pernicious anaemia and require regular B12 injections.

I have a new doctor whom I trust. However, when the time comes for my B12 injection, I wonder if he is doing it right because all the other doctors who have injected me with B12 have inflicted me with some level of pain (which I don’t mind as I am used to it and I know to expect it from the B12s). This doctor however inflicts no pain at all and the injection is done very quickly (I always have injections in upper arm) and I can’t help wondering if he is doing it right (He does not hold the needle perpendicular to the skin but slanted too). I have not dared raising the question with him though I have mentioned how painless his injections are. Should I be more open and discuss this with him or is he possibly aware of a way of injecting this B12 which most other doctors don’t know about?

I am 56, female.