I had the exact situation. My account said it traded on the ex. date seeming like I should receive the div. but I did not get the it. It makes sense. The only reason it would get exercised early is to get the Div. so I am pretty sure you will not.
Mostly the reason why you got called in the first place was for someone to get the 1.40 dividend. A .50 premium. It will happen everytime. You got to keep a months worth of time decay in one day. Be happy with that. I think ex divi works at the close of the day. Not sure but ask a rep over there as they are usually good like that.