After ttc for a year I've splashed out the outrageous price for a Persona kit. I'm in day 16 of my first month and there is still no "o". Two days ago my second line was a faint blue, yesterday it was really strong and I was convinced there would be an "o" today, but today there is no second line at all. Does anyone have any advice? Do you think I've ovulated? My cycle last month was 25 days, but it does vary. Would also appreciate hearing any other Persona stories.