Can someone please help me?

I'm 10 days off from my period. I missed a few pills about a week ago and my last period was a week early. All through this time I've had unprotected sex and today I woke up to cramps and not spotting but not really bleeding. It's brown and hasn't become much heavier it's enough to have to wear a pad or a panty liner is this implantation or maybe just break through bleeding? My friend thinks I'm pregnant and thinks it's implantation. What do you think?