If you bleed, it means you pierced a blood vessel (artery, vein, etc) and you should move your injection
speaking of bleeding injections...
I was pinning someone... This was the most fucked up shit I seen. As I pulled out, blood squirted out!! Like a fucking movie! It was actuallyyy pretty interesting to see this, and I laughed!
It's normal to bleed, just stated above, you nicked a vain. You'll be fine.
When in doubt you can always start using the Z-track method:
Overly wordy explanation but I'm too lazy to find you a better version. Use google:
Z-Track Injection Study Guide & Homework Help - eNotes.com
Lol like a BOSS!