Can Spotting After Unprotected Intercourse Be Symptoms Of Implantation Bleeding?

I stopped my birth-control about two month ago.. About a week ago I had unprotected sex with my boyfriend... I haven t gotten my period since I stopped my birth-contort may I add. Then yesterday day I started to bleed but more like spotting not heavy at all.. Today I had red pink and now red and brown discharge mixed .. Could this be implantation bleeding.. Doesn t look like my period more like spotting thur out the day. Please help.