anyone know?

So recently my SO and I had sex but there was a mishap with the condom (it came off inside me) my period is always without a doubt on time but this month it was 3 days late and then on the 4th day AF came but I only bled for 2 days and it was of medium flow now I have pink spotting only when I wipe..my periods always last 5-6 days so it's really worrying me..does anyone know what it might mean??