injection-blood-ummmmm?

i was injecting some prop into my glutes and i did it right iam sure of it. tested to see if i hit a blood vessel and no blood. finished injecting it and waited bout 10 sec. then pulled needle out, then i started bleeding, not to say that it was a whole lot or anything but it just caught me by surprise. i think i may have moved the needle a bit when i was injecting it. could i have maybe punctured a blood vessel. but other than that it is not bleeding anymore and the prop always goes in pain free. and i hardly ever have any pain the following days. could that be cause i am use to it? well thanks guys and gals for thakin the time to read and respond. peace