Ok, sorry if this is TMI, but all day today, my butt has been itching REALLY BAD!! There is one spot on my left cheek that has been itching, and it's that burning, deep type of itch, that is AWFUL! Well, today when I got home, I looked at it in the mirror, and there is a big red spot, and it's hot and warm, and there is a lump (LOL, that sounds lovely........

) I know it's from an injection site, but is it something I should worry about???? I'd say it's about 3 in across..........
Thanks!