I really just don’t understand....

Le

I have been testing my Ovulation since about three days after AF. Yesterday was predicted to be the day of ovulation. I have been testing two times a day. The lines have always been a lot lighter than the control line, but yesterday the line was almost non existent. I haven’t been drinking a bunch of liquids to cause me to urinate. I just use the restroom before I go to work, then when I come home to test.