Nervous about period not coming

Destiny

My last period ended the 1st of this month. I’m worried it’s not coming because <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">eve</a> says I’m 3 days late. My last period started the 26th. The period before that one was the 29th. I know a plan b can cause it to be a week early or a week late. I’m having no signs of my period coming. I’m trying not to worry myself but I’m starting to worry. Should I be worried?