Check your Google Play Notifications - Movie & Book deals ($1.99 movie rental, $3 or $4 off eBook) - YMMV
I went into the notifications tab of the Google Play store (click 3 line button in upper left, then click notifications). In there I had an offer for a $1.99 movie rental, $3 off an eBook over $4, and $4 off an eBook over $4.
YMMV of course, but just go check and see what you have. Might be lucky.