Question about test types

Terri • My name is terri Im from Essex uk, ttc baby no 3 for 2 years and have pcos
I have been using the one step pregnancy tests the cheapy ebay ones.... iv have second lines come up on more that one but line is not getting darker.... my question is has anyone else had this problem an did u do a different brand of test and get a clear result of a darker line. These test r confusing the hell out of me and don't wona believe it's a line if in fact it's not and it's just dodgy cheap tests. X