What are some of the signs of having an infection at the injection site. I hit a blood vessel for the first time the other day in my thigh, so i pulled the needle out and stuck it in again, no blood so i pushed it all in (2 mls of Omnadren 250). It didnt hurt at all really for the first 5 days afterwards and then today its been getting a little sore. No redness or anything, and really its not that sore but usually my shots hurt the most like the day after. Any advice? If it starts to get red i will be going to see the doctor.