So I finally started aspirating, but am a bit unsure. When drawing back on my last calf inject, I drew air bubbles, same with my glute and thigh, but then am afraid to shoot the bubbles back in. I figure they gotta come from somewhere, but they're the first things goin back in, and I don't feel right about puttin a little pocket of air in my muscle and then maybe fillin it up. Maybe I'm pulling back to hard on my draw? Or maybe their ok to shoot?