Unsure.

Jenifer
I've been using a <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">period tracker</a> including glow for the past 4 months. My period has started the days the tracker says it will. I am now 3 days late. I've been having slight lower back cramps. Not sure what's going on. Don't want to test and get my hopes up :(