Ovulation calculator vs my birth control pills HELP!

Jessica
I added an the <a href="https://play.google.com/store/apps/details?id=com.glow.android">ovulation calculator</a> to keep track. And something wasn't adding up. My birth control pills is showing me that I'm not due for my period until next week. But the app is saying I'm due for it. My last period was (sept 25) im due for my period (October 30)