I have been injecting for several years now . I had my gf do a glute shot for me a few mins ago . She has been injecting me for awhile now. She knows to asparite. I have never hit a vein . The injection went fine but when she pulled the syringe out I noticed there was a big drop of blood in the needle tip( blood was in the clear part of needle tip where it screws onto cylinder tube ). She did not notice the blood and she has gave an injection to someone else in the past and hit a vein and blood came back into tube not just the needle tip( clear part where it screws onto cylinder tube). Is this ok or is it something to be concerned about??