Dumb question- help!

So, how do you know exactly how many days post ovulation you are? I have trouble with the ovulation strips, I never get a real positive. On Saturday I got the closest to a positive, but not quite. And then it got lighter Sunday And then today a little darker again. I also had EWCM on Saturday so I'm guessing Saturday?? So am I technically two days past ovulation today (Monday)? Everyone seems to be so aware of their ovulation and I'm over here like...huh? Lol help!!