PLEASE HELP! Implantation vs Ovulation spotting

Mary
I ovulated last week I know for sure, and I'm not supposed to start my period until the 15th. For the past 3 days I have been spotting here and there and have been ridiculously tired. Everything either says its ovulation bleeding and I couldn't have implantation bleeding until a couple days before my period, or it says it's definitely implantation bleeding. Help! What have been your experiences? I know I won't know for sure until I take a test a few days from know, but I still want to know experiences. Also, I've had a few pains in what feels like my pelvic area on the left side.