So I went back on both of my apps today to see how many days past ovulation AF showed up. Both months were day 12 and day 13. Well today makes day 16 past ovulation took a test Monday morning and BFN. One of my apps said I was supposed to start on the 14 and I marked it as I didn't start moved my day to start the 16, my other app says I'm supposed to start on the 20, I'm not sure what is accurate???? Any advice?