Implantation or period?

<a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a> has made me so nervous about things I've never been nervous about before! <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a> says I'm gonna get my period in 2 days, I take my last BC pill today, and I just had the worst cramps in all of history. I really have to go to the bathroom every 15 minutes but when I pee no blood comes out, only light spotting when I wipe. My question is even though I'm pretty sure it's my period, can this still be implantation bleeding? Or am I just being silly and I should probably get my heating pad ready?