No, since the promo ended at midnight last night you would not have been sign up for the free trial and use it for a week and then add the promo, you would have needed to sign up for service right away and add the promo code.
You can certainly do the free trial now and try it out. There is a new promo code 35PLUS that gets you $10 off the current price, doesn't give a time period so possibly indefinitely until you leave or Visible removes it at their discretion(in the fine print).
