Fear of infection

ok so read the injecton pain thread like a million times now and also run a search in this site and others.

so i injected 3 days ago (left glut) and while there is no swelling or redness or heat its still sore and its not feeling like its getting better.

so i know theres a need for swelling heat and redness in order to be able to say that its an infection but im in fear. just wanted to be on the safe side