4 x <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">period apps</a> prediction 1 - 13th, 2 - 14th, 3 - 15th, 4 - 15th, which one is the most accurate in your opinions? my cycle is irregular and varies from 28-38 days and diff each time most of the time. I input all the same data into all apps got the above. My question is if taking preg test 1 day before period due (early test) which app prediction is the most accurate? & clue. I'm just not sure and getting anxious. I got a negative result 2 days before expected period but this is from only 1 app. Should I just wait until the 15th and test again to ensure an accurate 99% results? thank you