You should still be covered. It sounds like your didn't miss your payment, which is the only reason your policy would covered. The only thing that would change about your policy if your move your due date really depends on when your due date was originally and what it currently is. Sometimes you completely change when your due date is, you can miss a billing cycle. Again, all of this depends on the exact details of your policy so it is difficult to give an exact answer. In terms of your accident, I believe you should still be covered. Due dates are notices of bills to be paid. As long as you were not cancelled by the insurance for not paying they will honor a claim. I recommend checking out our short guide on claims info here
for additional claims info. Sorry to hear about your accident.