After upgrading my iphone4s to 6.1.2, it stopped vibrating.

After upgrading my iphone4s to 6.1.2, it stopped vibrating. I tried to change the settings and sounds. But nothing changes it. I even tried the iBrate app. I reset all the settings and it still doesn't work. Does anyone else face a vibration issue? It was working perfectly till the day before yesterday and got screwed after I upgraded it to 6.1.2.