That happened to me once and it hurt like hell for days. I know now when I get that weird feeling and my muscle starts twitching that im close to a nerve and I always pull out and re-pin in another area. I push the pin in extremely slow when pinning quads just so I can feel if im getting close to a nerve.

Ya buddy sounds to me like you hit a nerve. I hit one not too long ago and for three days it hurt so much. Just running my finger across my muscle hurt. I made a ibuprofen cream and rubbed it on the muscle at least two times a day. I couldn't bend it without pain for those three days. By day four the pain lightened up but it still hurt. It took six days before I was pain free.

NERVES BROTHER

If you get a twitch or a "kick back" in any muscle group pull out and re-pin..... even the oil resovoir near a nerve will give you pain for days..... just not worth it man when you can re-pin and stay comfortable especially when ED or EOD pinning.

I did this before and my guess is that you nicked a vein. Although the time I bruised bad, I also had blood shoot out of my leg when I pulled the needle out.

you went through a vein, and hurt the muscle and went wayyyy too close to a nerve, possibly a more major nerve.