Better Tests?

Ok so I have a problem with testing early and bought a bunch of those walmart cheapies...the purple first signals. Today was my third test and while it should probably be considered negative, there may have been a vvvvvfl (line got darker after time frame but scared it's just an evap)! Anyways...would y'all say that the first response test might show it? Is first response better or would you say that the first signals that I have are basically the same??