I'm sure I'm fine but after my injection tonight blood came trickling out, it stopped after some pressure. But is this normal cause it never happened before. Did I possibly go through a vein? I felt a weird sensation about half way when going in and of course I aspirated but why is it getting so hard to pull back on the stopper? First time was easy. Let's say I was aspirating and was in a vein (not through a vein) would it be as hard to pull the stopper back or would it pull back easily while filling with blood? Sorry but still learning. Thanks.