Would like opinions please

Ann
OK so two weeks ago my boyfriend and I had unprotected sex. I have had nausea, tender breasts and brown spotting Suppose to start my period Sunday (yesterday) 6-11-17. Well I have but it's very, very light to were all I need is to wear a panty liner and it's just a little on there. Could this be my period or maybe a sign of pregnancy (implantation)?