I opened my app today to start my log. I had a 20something percent chance to get pregnant today previously, and now it says 8%. I look back and it moved my fertile days up a day and therefore, each day changed percentage wise. My ovulation day even changed and of course, we didn't have sex that day. Very frustrated with following this app, but luckily I have <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">period tracker</a> that seems reliable.