So, when I noticed I had the darker red line I immediately took care of business just in case the line had been darker for a while. They say with Wondfo to do it after 24 hrs but before 48. So, if we had sex the day of and the day after could that be good enough. I felt myself ovulating. I mean, sperm should last at the last 3 days, right. I just don't know if I can fit in a session today. Lol