Hi, MyDaysX <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">period app</a> predicted my period to come Wednesday  24.5.17, I tested that day and negative, I then tested again on Friday 26.5.17 and again negative, fertility friend app predicted my period to come that day and <a href="https://play.google.com/store/apps/details?id=com.glow.android">glow app</a> predicted my period to come today and still no period, thoughts on when to test again? Thanks :)