Anyone have this problem before? You go to inject into the delt. Same pins you have been using for a long time. You poke through and start depressing the plunger... to no effect. Pushing as hard as you can, the plunger just wont move. You pull the needle out and a trickle of blood runs down. No big deal, just restick in a different spot and it went in just fine.
Did I just hit some scar tissue or something? I've never had that happen before.