Just won a game in OT, but the strange thing is that it went 2 Quarters???

So OT starts and I get a FG up 27-24 and this guys just taking his time and not even using his TO to go down the field and the quarter ends..Game over right? NOT...we get a 2nd OT quarter!!!! WHAT? OT is one quarter only! WTF? Did I just miss something about rules change?

I ended up winning as he finally went 4 and out.