I have noticed that when I do have any irritation after an injection, it is usually several inches below the actual injection spot. I haven't had any swelling, though- I'd call your Dr. about it just in case it's an allergic reaction or something.
Hunh. I mean, I'm wary calling, I don't want to go in I don't have the time, but yeah, it's still swollen this morning and B pointed out it's warm to the touch. I iced it last night.