LH line GONE!

I posted earlier today about the line on my opk being lighter than what it was a few days ago. I tested again this evening, and there was no line at all! Or I should say, barely visible! Took Clomid and Femara. It's been 4 days since my last pill. I have PCOS and this is my 1st time using an opk. Does anyone know what's up? I'm only on day 13 of my cycle which averages 30 days. I couldnt've missed ovulation l could I? I've been testing and the lines havent showed positive!