December 20 I started period. It ended on the 23rd. I had unprotected sex on the 29th and 31st of…

December 20 I started period. It ended on the 23rd. I had unprotected sex on the 29th and 31st of December through new years 12am. Today is the Friday January 6th I wiped when I ruined and noticed light pink bleeding. Is it possible that it could be implantation bleeding? Or something else?