So I'm at the first month using glow. And I was just wondering about something! I have a bit irregular period, and the <a href="https://play.google.com/store/apps/details?id=com.glow.android">glow app</a> said I was going to get my period yesterday. But it didn't show up, so I push the button "I'm late". But then it said my period would start on the 14th! So I'm a bit confused, when should I take a pregnancy test?