I was bitten by 3-4 ants on Nov. 7, and the spot swelled up that Sunday morning and is still swollen today, it's turning pinkish purple, what do I do?

Not much. This is a toxic reaction to ant saliva and it will resolve. Perhaps applying cold compress or a dab of otc hydrocortisone will help. If redness begins enlarging or pain worsens, then an antibiotic is indicated.
Insect bite. insect bite can cause swelling reddness and pain on the site . see pcp for medication. meantime apply ice , elevate limb to decrease swelling.