I'm well into SI (just did my second!) and using the same needle to draw the liquid out of the ampoule as to inject, which doesn't seem to be a problem except that I can't get it all out of the ampoule no matter how I try. Tonight I ended up injecting just over 1/2ml. I've tried pushing air into the ampoule, tipping it upside down, on its side, repeatedly trying to draw more up. Help! What am I doing wrong?