I don't inject methamphetamine very often due to my constant misses. The last time I attempted to inject I did it in my cephalic vein on the outer side of my forarm. I was able to get the needle in the vein but at some point after injecting some of the shot, my needle slipped out. I then went back in to attempt to inject the rest, I thought I was in after a few attempts and did the rest. Immediately after I had a nasty bruise and a lot of pain. The blood spread almost all the way around my arm, the vein was obviously leaking. I am now on day 4 following this trauma and all that's left of the injury is a red bump. However; I have had a headache for 3 days now behind my right eye. I'm concerned the two may be connected....I have a cold as well. when should I be concerned enough to see a doctor?