Compare unplanned with other words:
unplained vs. unplanned
unconstrained vs. unplanned
planned vs. unplanned
encounter vs. unplanned
structure vs. unplanned
organization vs. unplanned
advance vs. unplanned
through vs. unplanned
thought vs. unplanned
spontaneous vs. unplanned
intended vs. unplanned
impromptu vs. unplanned
random vs. unplanned