Okay! So I have marked every period sense 2011 on my phone on a different app! I just got this one and started to use it as well! Well my last period I some how forgot to mark the right date but I tried to count back and I'm pretty sure I had it right! There's normally 29 days in my cycle! Well both apps say I'm a day late! And I have had unprotected sex and on ovulation day and a couple days before and after! I'm having cramps and other signs of my period! But my only problem is I'm not sure when I'm really supposed to start! I just needed to get that off my chest! Ahh!