Getting a passcode after I updated IOS9 on my iPhone6?

I updated my iPhone 6 last night, and when I woke up and tried to see log into my phone, it needed a 6 digit passcode. I've never set a passcode in my phone before, and I've asked my family if they set a passcode, but all of them said no. Why is there suddenly a passcode? Is there a way to fix this? I can't log into my phone.

Thank you in advance.

Added (1). Hi guys, I updated my iPhone 6 plus last night, and when I woke up and tried to see log into my phone, it needed a 6 digit passcode. I've never set a passcode in my phone before, and I've asked my family if they set a passcode, but all of them said no. Why is there suddenly a passcode? Is there a way to fix this? I can't log into my phone.

I'm not good at smart phones-same thing happened to me yesterday. Well I made up a 6 numeral pass code, then went to settings. THERE you have to use it again, hit something like no pass codes and shut phone off completely. That's how I did it. Fiddle with it and you'll wind up with no pass codes. But the answer is in settings.