many BFPS then 1 BFN!??

I'm panicking right now.  The last few days I have been getting BFP. I set up an appointment with doctor next week. This afternoon I took a first response digital and it said "NO". I've been getting all positives now I'm getting a no. This is my first baby so I'm extremely said. I'm waiting to take the first response dye test. I know sometimes digital tests aren't sensitive. Has this happen to you before?!?