I believe First Response always has a printable coupon on their site. Not sure if you can get First Response in Canada, or if you were talking about in-store coupons or online coupons. But I hope that helps.
I know the First Response pregnancy test box comes with coupons for $ 2.00 off your next PT and one for $ 2.00 off a fertility test or Ovulation Predic. Test. You would need to buy a box of their PT first ( which you'll be using later on anyway), but then you could save some cash on the OPK. Hope it helps....
Re: Coupons...
Us Canadians get screwed on coupons!
Check out www.makeababy.ca they have cheap test strips for sale.