I've been reading a lot of threads on other people having this similar problem but not exactly. I started my 4th week yesterday (Sunday) in the glute as usual but this one was different. Was a little more painful than the other pins and began to hurt immediately after. Not a throbbing pain or anything just sore. Well today it is swollen and sore as well. I was wondering if maybe I hit a tendon or something. It wasn't a vein I'm sure because I check before injecting and I am very clean. I use needles right out of the package and change needles before injecting. Anyway just trying to get feed back on it. From what I have read from other people its nothing out of the ordinary with straight test sometimes so I'm not worried just concerned because this is the first problem I've had.