Just wondered if anyone had used these and had success? I just took one yesterday and got the "smiley face" so does this mean I am about to ovulate, or that it could be as long as three days until it happens. Also, if you get a surge, how long does it last...i,e, could I be "surging" for a number of days? Sorry - i know I sound dense, but nthe instructions are a bit vague!