My iphone for the first time vibrate twice for one message I was talking in face time with my husband and he sent me a message to I message, my phone vibrated but there wasn't a sms or notifications for the sms. 

After 3 seconds my phone vibrate again and then show the sms. 

The question is how can iphone 5 vibrate twice for same sms.
Normally you could disable the "Repeat" in

go to settings > notifications >  select messages  > scroll down to repeat alerts > select never /.