Wondfo pregnancy tests vs name brand?

Caroline • Had an ectopic pregnancy resulted in loss of left tube in 2013. Now mommy of a baby boy and thinking of trying for another soon.
I've been trying for over a year and have never even gotten to the point of testing for pregnancy because I am not an early tester. I had a couple of cheap tests laying around and decided to test this am. I am two days past AF, DPO 17. I swear the wondfo tests have really faint lines on them but can't tell if that's just indent?
I ran out and bought some first response ones and tested just now but they are totally BFNs. 
Is that normal? Or the cheapie ones are just not very reliable?
Thanks for any advice!!!