Redness again in Quad?

[wrestless]

Guys, can someone give me some sort of reason that this happens in my right Quad only, and only sometimes like 1 in every 15 pins. I just started a Prop cycle on Monday at 300 mg per week. Pinned once in each Butt cheek a little sore but normal after being off. On Friday did my third pin in my right quad and the next day very painful and today noticed redness, luckily still have some antibiotic from 9 months ago and just started taking again. Just frustrates the shit out of me because I am very careful using different pins for extracting and injecting. Any help on this one ?

[gixxerboy1]

its not always sterile injecting practices. you are putting chemicals, oil and ba into your muscle. A reaction sometimes in normal