I've had bad injections a lot over the years. Worried about it being an abscess, waited. Always went away with time. That's not to say you don't have one but they aren't common if you use proper methods and sterile environs. Most likely oil caught in fascia and traveling down your arm plus tissue irritation from moving the needle around. If you're really worried about it though it's always safest to see a doctor but then you have to go on record as having injected yourself with AAS. Tough call.