First response gold digital problems?

Hillary
Hey ladies! AF due today with no signs of her yet.. I tested this morning with a first response digital and got a big fat NO :(. I popped it open because I'm a psycho and it looked like the urine hadn't gone across the whole paper. This is my first month trying femara and I'm sure I ovulated! I've also never gotten to my actual period due date without spitting before, and I've been having tons of clear cm. Has this happened to anyone before?