It might just be the gear, IDK. I've never run a blend like that so I cannot comment. I do think it's safe to say that when you start pinning, the first is the worst, so it should only get better from here. The only other advice I have on choosing the spot for the injection, is first, look at any/all of the links or just google IM self injection to see the general area that they recommend. This will help you avoid nerves and blood vessels, but after you've selected the basic area, flex you muscle and just look at where it's the thickest or most pronounced. Remember it is an intramuscular injection, so make sure you are hitting thick part of the muscle, but also don't assume that anywhere you see muscle is a safe place to inject, that's why you also need to check the guides or the odds of hitting something you don't want to hit go up considerably. It should go without saying, but make sure the muscle you are pinning is completely relaxed and that you can keep it that way throughout the whole process.