Since I have been using <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a> as my <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">period tracker</a>, I couldn't help but notice I've been a little off each time my periods are supposed to start. I'm now apparently 7 days late and I have protected sex regularly, should I be worried? I'm not as concerned since I have been working out like crazy, have changed my eating habits, and have been stressed.