where did the lines go??

I'll start off with I'm new to using opks. I'm on cd9 and I've been testing twice a day, every day has been a negative but the test line was there, maybe about half as dark as the other line but it was absolutely there. I have ewcm everyday since cd7, so I figured with all that I was probably going to ovulate soon... but today I took an opk and the test line is almost completely gone and my cm is more of a brownish tinted color. I'm bummed. what does this mean?? I couldn't have possibly missed my lh surge could I?