Could be all those things mentioned. Bring it to the attention of your doctor or go to the ER if you get a fever above 102 or have red streaks coming from it, is large, find others. Usually antibiotics are given to see if it resolves it or gets smaller, or under other conditions may want it removed right away. Even a cyst or abscess, can cause further complications, fever, go systemic, even travel to the brain, other organs. I had one surgically removed one month prior to cancer from my face, and that had MRSA, probably hospital acquired, and was in the hospital for 20 days, since it also went systemic. After that, I changed by razors frequently, used disposable ones instead. Also, look at your immune system, I have diabetes, so it's easier to get infections, have delayed healing. Idk, if you mentioned having a full blood work up, like complete blood count, complete metabolic count, plus others the doctor desires, to see if anything is out of range or abnormal.

Good luck.