I know someone this recently happened to. Check THIS THREAD for some information regarding infections. Sounds like you had a bad shot. Pin moved around and probably got some oil in the fatty area. The oil will absorb, but it will take 7+ days or so. Use a warm compress to help along. Either a heating pad, or one of those microwavable moist heat pads with rice in them. Soaking in a hot bath also helps. Massage the area as well. Also, keep an eye on the area, and monitor your body temp. I believe it's too early for an abscess to form. Also, you may want to look into keeping some form of antibiotic on-hand, just in case. Let me know if you have any other questions.