Idk if I'm pregnant or not

Ok my last fertile day was the 26th of February and I had sex that day. One of my <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">period apps</a> told me my period is suppose to come today but I haven't had it yet. But this app glow said my period is coming this Tuesday. I've been cramping and tender breast but no period yet