Important safety tip for new needleheads
Ok, this might be an obvious tip to the regulars, but I thought I'd offer it as a "heads up" to newcomers just in case it happens to them...
Sometimes you slide the needle in, pull back, see blood and now you're home free! Just gently push down on the plunger and await bliss...
But halfway down the plunger suddenly feels like it's gotten stuck! You try to push down but for some reason the resistance has doubled...
STOP RIGHT THERE! This is a sign that you've either slipped out of the vein or accidentally pushed right through it during the shot. No matter how desperate you are for your fix, you need to pull out and start over. If you push down hard and try to complete the shot all you're going to do it swell up, bruise and, worst of all, loose whatever is left of your shot!
Don't worry, it happens to the best of us. We can't see inside our veins and sometimes we've registered right on the edge of the vein... Try as we might, its hard to keep that needle 100% steady (especially if you're withdrawing) so the slightest movement can "unregister" you in a heartbeat.
This is why some people pause in the middle of their shot - they pull back the syringe a bit and look for a little blood, just to double check that they are still inside the vein.
Personally, I don't bother re-registering, since if you suddenly poke out of the vein its pretty obvious (the needle gets stuck, you see the skin puff up in reaction to the drugs and sometimes it might even hurt).
In any case, always pay careful attention as you shoot - registering is a large part of the battle, but making sure you STAY registered is important as well.
Oh and stay away from mad dogs with rabies, they can ruin your shot too.