Implantation Bleeding?

Hello All,

I have an interesting question. My last period was 9/15. It was 3-4 days. The first day and a half was more like mucusy with brown and red blood and then the third day was actual regular flow. Fourth day, regular then lighter towards the end of the day. This afternoon, I went to the bathroom and had pinkish brown spotting when I wiped. Any idea what this could be? SO and I have BD’d ALOT over the last 30+ days but im sure this CANT be IB...could it? My cycles have been between 25-34 days the last 6 months so Im not sure when I even ovulated.