Rant about Internet cheapie tests!

So after quite a while ttc I've come to the conclusion that I will never use Internet cheapies again! I was so adamant I had finally got my bfp after over 2 years of ttc. I've never had even a hint of a vfl but the other evening I got what everyone said was my bfp. I was so unbelievably happy until I decided to make sure with a frer and its completely negative! I really dont understand how a test can provide such a dark line when it's completely false. These were fermometer rapid strip tests from amazon