Faulty unit? 6 days of testing, kit started acting funny last two days.

I've been using the advanced digital kit. Yesterday, the kit didn't start blinking for about two minutes (says it's supposed to take 1 minute), but I got a result afterwards (low fertility). The same thing happened this morning, but I got an error code. I repeated the test as instructed and it again took over two minutes to start blinking. The second time I got a result - low fertility. I also starting showing EWCM last night and this morning. What's going on? Is my unit faulty? I'm following the instructions to a T. If it is faulty, how can I get a replacement?