Why am I spotting??

Sarah

So my period was about 2 weeks ago.it wasn't like a normal period it was spotting I didnt even fill a tampon. I didnt even have to wear one. I was with my SO during my peak times and it shows my O day as today. We did the Bd as you can see marked on the calendar and the past 2-3 days I've had bright pink and brown spotting only when I wipe. Do any of you ladies know what this could possibly mean? Could I be pregnant ? I also did the BD on the last day or the 2nd day after my period I just didnt mark it