I did a shot in my bicep three days ago and it wasn't the best of shots. I aspirated but blood came back into the syringe after I was done, not much, but a little. Anyway, since then the area has been a bit warm and red, but this is common. I've been using the same stuff for months and this same vial for a couple weeks and no previous problems. But this one hurts exceptionally more (trying to entirely straighten my arm is like pulling fingernails) and yesterday I came down with a bit of a fever. Went to 101 but today is down to 99.4. I used a new needle, new barrel, cleaned everything with alcohol as always. Should I be worried?