Okay, I just injected 500mcgs of vitamin b-12 into my right delt. it hurt more than it usually does when pushing the needle in. i aspirated and there was no blood, just a little air bubble. when i removed the needle, a large bead of blood came out. now, my shoulder hurts more than it usually does, and i'm not quite sure, could be paranoia, but my arm feels a little tingly. i hope this is enough info to tell, but is there anything i should worry about, or am i just being paranoid?