Possible implantation

We had intercourse on the 28th of November and the 2nd of this month then 2 days later i had some light cramping and spotting of dark red and brown discharge so i dont know if it was spotting it was only showing when i wiped and only happened the 4th and 5th then completely stopped then we had intercourse again the following Sunday my period is normally not like that it will last 4 to 5 days and i have to always use a pad all day and at night it is never this short or light