I, personally, would have shot into a different vein or place altogether. If what you did was the same meth/dose/poking as you have done in the past and if you're confident that it's safe to inject, I would have just moved onto a different spot.
Perhaps the cut or the shit itself is bunk. If that is the case, DO NOT INJECT.
Honestly, you're safer breaking the point off the needle and plugging it. (Just do it. Tell everyone you didn't and never will. That's a secret you don't need to share. You get high as fuck, yo.