Chances of being pregnant?!

Well according to this app my period was due today. I had "done the do" if you get what I mean, on what it said was 2 days after my fertile window ended. Well today since I didn't get my period, the app updated to say that I "did the do" on the last day of my fertile window and it changed from 3% to 8% chance of pregnancy but is that out of 10? 100%? Do you think my period is just late or do I actually have a chance this month?