how long should you wait before taking a pregnancy test

According to <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">eve</a> my period is 2 days late. I've been pretty stressed out this month and I'm feeling pretty sick. How long should I wait before taking a test?? 
Update took 2 tests and they're negative still no period. Getting worried  😩