Could Yellow Gunk On Applying Neosporin Be The Indication Of Infection?

I have wound on my leg from a nail hanging out of my chair. The wound is deep, and because I have school, i couldn't wash and clean it, so i put neosporin, and bandaged it up, but after school, which was six hours, I went home and used alcohol to disinfect it. I've been doing it since, and it's bee 3 days. After I take off the bandage, some of the neosporin turns yellow. Is this a sign of infection?