|When I was opking for a study I had to call and make an appointment for an US for 36-48 hours later, and there was only ONE occasion that they could not confirm ovulation.
You tend to ovulate at the peak of your cm, that's why it changes so drastically with in a day or so. You'll see I had really wet cm the day of Ovulation (and felt slippery), but the next day I lost the slippery feeling and was just had really wet cm. I knew then that I had ovulated for sure.
I also had the major O pains right when I should have, I had two days of pain because I use "days" meaning from when I wake up, to when I go to bed. So If I stay up until 6am, that is the day before, not the calender day (I'm consistent with this)... I probably ovulated at 2:30ish Am on the day after it shows the egg.. but close enough for moi. I was at least awake to know it was happening.
This is my fist clear "normal" cycle since coming off the pill. If we get the egg, with my history there is a good chance it could be a chemical.