I made an injection in my ass, pulled back needle & no blood, after shot when pulling out slow, blood started pouring out though stopped after little presure applied, think i hit a vien. When looking @ needle after there was a little bubble of blood in the top end tip between the needle & pulunger where they conenct, should i worry or could this be from the withdrawl of the needle, it' s been a day since. Just want to know if this has happened to anyone.